X-Ray packet V2.pdf

Equipment*Packet:*X"Ray&Systems*UMDNS*#:&13267&Date*of*Creation:&November&21,&2015&Creator:&Complied&by&Cassandra&Stanco&for*Engineering&World&Health&(EWH)***Equipment*Packet*Contents:*This&packet&contains&information&about&the&operation,&maintenance,&and&repair&of&x"rays&systems.&&Part*I:*External*From*the*Packet:** 1. An*Introduction*to*XCRays:*&PowerPoint&*Part*II:*Included*in*this*Packet:** 1. Operation*and*Use:*a. Brief&Overview&of&X"Rays&(p.&3)&b. Brief&Introduction&to&Stationary&Diagnostic&X"Rays&(p.&4)&c. Detailed&Introduction&to&X"Rays&(p.&5"16)&d. Radiation&Dose&Management&(p.&17"25)&e. Operation&and&Use&of&X"Ray&Systems&(p.&26"39)&2. Diagrams*and*Schematics:*a. Figure&1:&X"Ray&Tube&and&Housing&(p.&41)&b. Figure&2:&Example&of&an&X"Ray&(p.&42)&c. Figure&3:&WHO&Specification&for&Analog&Diagnostic&X"Ray&(p.&43"47)&d. Figure&4:&WHO&Specification&for&Digital&Diagnostic&X"Ray&(p.&48"50)&3. Preventative*Maintenance*and*Safety:*a. X"Ray&Preventative&Maintenance&Checklist&(p.&52)&b. Preventative&Maintenance&for&X"Ray&Viewers&(p.&53)&c. Safety&and&Fault&Detection&in&X"Ray&Systems&(p.&54)&4. Troubleshooting*and*Repair:**a. X"Ray&Troubleshooting&Table&(p.&56)&b. X"Ray&Troubleshooting&Flowcharts&(p.&57"62)&5. Resources*for*More*Information*a. Resources&for&More&Information&&(p.&64)&b. Bibliography&&(p.&65)&* &*
1




***1.*Operation*and*Use*of*XCRay*Systems****Featured*in*this*Section:***Strengthening&Specialised&Clinical&Services&in&the&Pacific.&User(Care(of(Medical(Equipment:(A(first(line(maintenance(guide(for(end(users.&(2015).&&&Wikipedia.&Basic(Physics(of(Digital(Radiography/The(Image(Receptor.&&Wikibooks.&Downloaded&6/25/2014.&Retrieved&from:&https://en.wikibooks.org/wiki/Basic_Physics of Digital_Radiography/The_Image_Receptor&*WHO.&“Radiographic,&Fluoroscopic&System.”&From&the&publication:&Core(Medical(Equipment.&Geneva,&Switzerland,&2011.&&&WHO.&“X"Ray&Diagnostic&Equipment.”&Maintenance(and(Repair(of(Laboratory,(Diagnostic(Imaging,(and(Hospital&Equipment((WHO:&1996),&p.&121"134.&&&Wikipedia.&“&X"Ray.”&Wikipedia,&pp.&1"17.&Retrieved&from:&https://en.wikipedia.org/wiki/X"ray&&&* *&&&&* *
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User Care of Medical Equipment – First line maintenance for end users


72


Chapter 4.22 X-Ray Machines


Function


X-Ray machines are used for imaging bones and hard tissues and diagnosing fractures, joint defects,
choked lungs etc. Sometimes contrast agents are also used to highlight any defects in the abdomen under X-rays.


How it works


X-rays are high energy electromagnetic waves. The transformer produces a high voltage that directs
electrons onto a target in the machine head. X-rays are produced by the target and are directed into beams by a
collimator towards the human body. Soft body tissue absorbs less X-rays, i.e., passes more of the radiation,
whereas bone and other solids prevent most of the X-rays from going through. A photographic film or electronic
sensor displays how much X ray has passed through, forming an image of the interior of the body. Bone appears
nearly white, because few X-rays strike the corresponding part of the film, leaving it largely unexposed; soft
tissue allows much more radiation to pass through, darkening the film in those places.


Users must ensure proper radiation safety protocols and supervision are in place. See Chapter 9 for
suitable references and further information.






collimator


X-Ray tube head


film cassette /
sensor


(control panel and transformer not shown)


patient
table


Strengthening Specialised Clinical Services in the Pacific. User Care of Medical Equipment: A first line maintenance guide for end users.


(2015).


Brief Overview of X-Rays


Strengthening Specialised Clinical Services in the Pacific. User Care of Medical Equipment: A first line


maintenance guide for end users. (2015).


3




http://www.who.int/medical_devices/en/index.html
© Copyright ECRI Institute 2011 (not including the GMDN code and device name).


Reproduced with Permission from ECRI Institute’s Healthcare Product Comparison System.


© Copyright GMDN Agency 2011. GMDN codes and device names are reproduced with permission from the GMDN Agency.


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n Health problem addressed
This technology is effective in arthrography, bronchography,
gastrointestinal and biliary tree studies, hysterosalpingography,
intravenous and retrograde pyelography, myelography, and
sialography. Other applications include locating ingested foreign
materials; localizing lesions for needle aspiration or biopsy;
highlighting congenital anatomic abnormalities; diagnosing
congestive heart failure; and evaluating chest pain.


Product description
These devices consist of a combination of a patient support unit
(usually a table base and a movable tabletop), an under-table
x-ray tube and holder, x-ray generators, a power-assisted spot-
fi lm device, an image intensifi er, radiation shields, a Bucky fi lm
tray, an overhead x-ray tube and ceiling support for follow-up
radiography, and a control panel.


Principles of operation
Most R/F systems allow spot fi lming of the image to produce
an x-ray fi lm for later detailed study by the radiologist and for
fi lm archiving. For routine radiography and follow-up x-ray
scans after studies that use contrast media (e.g., gastrointestinal
studies), most systems include an under-table Bucky tray for use
with an overhead x-ray tube.


Operating steps
Patients are positioned on the x-ray table and a catheter
inserted (procedure-dependent). The x-ray scanner will be used
to produce fl uoroscopic images. Depending on the procedure,
a dye or contrast substance may be injected into the patient via
an IV line in order to better visualize the organs or structures
being studied. After the procedure is complete the IV line will
be removed.


Reported problems
Typical problems include mechanical issues; unexpected failures
of safety features; overexposure or unexpected exposure to
radiation; breakage or weakening of mechanical supports;
overheating in drive motors; table misalignments; inadequate
radiation shielding; and noncompliance with regulatory codes.


Use and maintenance
User(s): Radiologic technician
Maintenance: Medical staff; technician;
biomedical or clinical engineer
Training: Initial training by manufacturer and
manuals


Environment of use
Settings of use: Hospitals; private practices;
clinics; stand-alone imaging centers
Requirements: Radiation shielding (room,
mobile, or overhead); stable power source


Product specifi cations
Approx. dimensions (mm): Confi gurable
Approx. weight (kg): Confi gurable
Consumables: NA
Price range (USD): 415,000 - 1,150,000
Typical product life time (years): 10
Shelf life (consumables): NA


Types and variations
Over- or under-table x-ray tube; C-arm;
remote control; direct control


Radiographic, Fluoroscopic System
UMDNS GMDN
16885 Radiographic/Fluoroscopic Systems, General-


Purpose
37645 Stationary basic diagnostic x-raysystem, digital


Other common names:
General-Purpose Radiographic/Fluoroscopic Systems; Radiographic/Fluoroscopic Units, General-Purpose; Tables,
Radiographic/Fluoroscopic; Direct-Controlled Radiographic/Fluoroscopic Systems; Remote-Controlled Radiographic/
Fluoroscopic Systems


Brief Introduction to Stationary


Diagnostic X-Rays


WHO. “Radiographic, Fluoroscopic System.” From the publication: Core Medical Equipment. Geneva,


Switzerland, 2011.


4




X-ray 1


X- ray


Hand mit Ringen (Hand with Rings): print of
Wilhelm Röntgen's first "medical" X-ray, of his
wife's hand, taken on December 22, 1895 and
presented to Professor Ludwig Zehnder of the
Physik Institut, University of Freiburg, on 1


January 1896[1] [2]


X-radiation (composed of X-rays) is a form of electromagnetic
radiation. X-rays have a wavelength in the range of 10 to 0.01
nanometers, corresponding to frequencies in the range 30 petahertz to
30 exahertz (3 × 1016 Hz to 3 × 1019 Hz) and energies in the range 120
eV to 120 keV. They are shorter in wavelength than UV rays. In many
languages, X-radiation is called Röntgen radiation, after Wilhelm
Conrad Röntgen, who is generally credited as their discoverer, and
who had named them X-rays to signify an unknown type of
radiation.[3] :1-2


X-rays from about 0.12 to 12 keV (10 to 0.10 nm wavelength), are
classified as "soft" X-rays, and from about 12 to 120 keV (0.10 to
0.010 nm wavelength) as "hard" X-rays, due to their penetrating
abilities.


Hard X-rays can penetrate solid objects, and their largest use is to take
images of the inside of objects in diagnostic radiography and
crystallography. As a result, the term X-ray is metonymically used to
refer to a radiographic image produced using this method, in addition
to the method itself. By contrast, soft X-rays can hardly be said to
penetrate matter at all; for instance, the attenuation length of 600 eV (~
2 nm) x-rays in water is less than 1 micrometer[4] X-rays are a form of
ionizing radiation, and exposure to them can be a health hazard.


The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic
radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma
rays).[5] So older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation
shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays.[6] However, as shorter wavelength
continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were
discovered, the wavelength bands largely overlapped. The two types of radiation are now usually distinguished by
their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.[5] [7]
[8] [9]


Units of measure and exposure
The measure of X-rays ionizing ability is called the exposure:


• The coulomb per kilogram (C/kg) is the SI unit of ionizing radiation exposure, and it is the amount of radiation
required to create one coulomb of charge of each polarity in one kilogram of matter.


• The roentgen (R) is an obsolete traditional unit of exposure, which represented the amount of radiation required to
create one electrostatic unit of charge of each polarity in one cubic centimeter of dry air. 1.00 roentgen =
2.58×10−4 C/kg


However, the effect of ionizing radiation on matter (especially living tissue) is more closely related to the amount of
energy deposited into them rather than the charge generated. This measure of energy absorbed is called the absorbed
dose:


• The gray (Gy), which has units of (Joules/kilogram), is the SI unit of absorbed dose, and it is the amount of
radiation required to deposit one joule of energy in one kilogram of any kind of matter.


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


Detailed Introduction to X-Rays


5




X-ray 2


• The rad is the (obsolete) corresponding traditional unit, equal to 10 millijoules of energy deposited per kilogram.
100 rad = 1.00 gray.


The equivalent dose is the measure of the biological effect of radiation on human tissue. For X-rays it is equal to the
absorbed dose.


• The sievert (Sv) is the SI unit of equivalent dose, which for X-rays is numerically equal to the gray (Gy).
• The Roentgen equivalent man (rem) is the traditional unit of equivalent dose. For X-rays it is equal to the rad or


10 millijoules of energy deposited per kilogram. 1.00 Sv = 100 rem.


Medical X-rays are a significant source of manmade radiation exposure, accounting for 58% in the United States in
1987, but since most radiation exposure is natural (82%), medical X-rays only account for 10% of total American
radiation exposure.[10]


Reported dosage due to dental X-rays seems to vary significantly. Depending on the source, a typical dental X-ray of
a human results in an exposure of perhaps, 3,[11] 40,[12] 300,[13] or as many as 900[14] mrems (30 to 9,000 μSv).


Medical physics


X-ray K-series spectral line wavelengths (nm) for some common target materials.[15]


Target Kβ₁ Kβ₂ Kα₁ Kα₂


Fe 0.17566 0.17442 0.193604 0.193998


Co 0.162079 0.160891 0.178897 0.179285


Ni 0.15001 0.14886 0.165791 0.166175


Cu 0.139222 0.138109 0.154056 0.154439


Zr 0.070173 0.068993 0.078593 0.079015


Mo 0.063229 0.062099 0.070930 0.071359


X-rays are generated by an X-ray tube, a vacuum tube that uses a high voltage to accelerate the electrons released by
a hot cathode to a high velocity. The high velocity electrons collide with a metal target, the anode, creating the
X-rays.[16] In medical X-ray tubes the target is usually tungsten or a more crack-resistant alloy of rhenium (5%) and
tungsten (95%), but sometimes molybdenum for more specialized applications, such as when soft X-rays are needed
as in mammography. In crystallography, a copper target is most common, with cobalt often being used when
fluorescence from iron content in the sample might otherwise present a problem.


The maximum energy of the produced X-ray photon is limited by the energy of the incident electron, which is equal
to the voltage on the tube, so an 80 kV tube cannot create X-rays with an energy greater than 80 keV. When the
electrons hit the target, X-rays are created by two different atomic processes:


1. X-ray fluorescence: If the electron has enough energy it can knock an orbital electron out of the inner electron
shell of a metal atom, and as a result electrons from higher energy levels then fill up the vacancy and X-ray
photons are emitted. This process produces an emission spectrum of X-ray frequencies, sometimes referred to as
the spectral lines. The spectral lines generated depend on the target (anode) element used and thus are called
characteristic lines. Usually these are transitions from upper shells into K shell (called K lines), into L shell
(called L lines) and so on.


2. Bremsstrahlung: This is radiation given off by the electrons as they are scattered by the strong electric field near
the high-Z (proton number) nuclei. These X-rays have a continuous spectrum. The intensity of the X-rays
increases linearly with decreasing frequency, from zero at the energy of the incident electrons, the voltage on the
X-ray tube.


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


6




X-ray 3


So the resulting output of a tube consists of a continuous bremsstrahlung spectrum falling off to zero at the tube
voltage, plus several spikes at the characteristic lines. The voltages used in diagnostic X-ray tubes, and thus the
highest energies of the X-rays, range from roughly 20 to 150 kV.[17]


In medical diagnostic applications, the low energy (soft) X-rays are unwanted, since they are totally absorbed by the
body, increasing the dose. Hence, a thin metal sheet, often of aluminum, called an X-ray filter) is usually placed over
the window of the X-ray tube, filtering out the low energy components in the spectrum. This is called hardening the
beam.


Both of these X-ray production processes are very inefficient, with a production efficiency of only about one percent,
and hence, to produce a usable flux of X-rays, a high percentage of the electric power inputted is released as waste
heat. The designers must design the X-ray tube to dissipate this excess heat.


Radiographs obtained using X-rays can be used to identify a wide spectrum of pathologies. Due to their short
wavelengths, in medical applications X-rays act more like particles than waves. This is in strong contrast to the
application of X-rays in crystallography, X-ray crystallography, where their wave-like nature is more important.


To make an X-ray image of human or animal bones, short X-ray pulses illuminate the body or limb, with
radiographic film placed behind it. Any bones that are present absorb most of the X-ray photons by photoelectric
processes. This is because bones have a higher electron density than soft tissues. [Note that bones contain a high
percentage of calcium (20 electrons per atom), potassium (19 electrons per atom) magnesium (12 electrons per
atom), and phosphorus (15 electrons per atom). The X-rays that pass through the flesh leave a latent image in the
photographic film. When the film is developed, the parts of the image corresponding to higher X-ray exposure are
dark, leaving a white shadow of bones on the film.


To generate an image of the cardiovascular system, including the arteries and veins (angiography) an initial image is
taken of the anatomical region of interest. A second image is then taken of the same region after iodinated contrast
material has been injected into the blood vessels within this area. These two images are then digitally subtracted,
leaving an image of only the iodinated contrast outlining the blood vessels. The radiologist or surgeon then compares
the image obtained to normal anatomical images to determine if there is any damage or blockage of the vessel.


A specialized source of X-rays which is becoming widely used in research is synchrotron radiation, which is
generated by particle accelerators. Its unique features are X-ray outputs many orders of magnitude greater than those
of X-ray tubes, wide X-ray spectra, excellent collimation, and linear polarization.[18]


Detectors


Photographic plate
The detection of X-rays is based on various methods. The most commonly known methods are photographic plates,
photographic film in cassettes, and rare earth screens. Regardless of what is "catching" the image, they are all
categorized as "Image Receptors" (IR).


Before the advent of the digital computer and before the invention of digital imaging, photographic plates were used
to produce most radiographic images. The images were produced right on the glass plates. Photographic film largely
replaced these plates, and it was used in X-ray laboratories to produce medical images. In more recent years,
computerized and digital radiography has been replacing photographic film in medical and dental applications,
though film technology remains in widespread use in industrial radiography processes (e.g. to inspect welded
seams). Photographic plates are mostly things of history, and their replacement, the "intensifying screen", is also
fading into history. The metal silver (formerly necessary to the radiographic & photographic industries) is a
non-renewable resource. Thus it is beneficial that this is now being replaced by digital (DR) and computed (CR)
technology. Where photographic films required wet processing facilities, these new technologies do not. The digital
archiving of images utilizing these new technologies also saves storage space.


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


7




X-ray 4


Since photographic plates are sensitive to X-rays, they provide a means of recording the image, but they also
required much X-ray exposure (to the patient), hence intensifying screens were devised. They allow a lower dose to
the patient, because the screens take the X-ray information and intensify it so that it can be recorded on film
positioned next to the intensifying screen.


The part of the patient to be X-rayed is placed between the X-ray source and the image receptor to produce a shadow
of the internal structure of that particular part of the body. X-rays are partially blocked ("attenuated") by dense
tissues such as bone, and pass more easily through soft tissues. Areas where the X-rays strike darken when
developed, causing bones to appear lighter than the surrounding soft tissue.


Contrast compounds containing barium or iodine, which are radiopaque, can be ingested in the gastrointestinal tract
(barium) or injected in the artery or veins to highlight these vessels. The contrast compounds have high atomic
numbered elements in them that (like bone) essentially block the X-rays and hence the once hollow organ or vessel
can be more readily seen. In the pursuit of a non-toxic contrast material, many types of high atomic number elements
were evaluated. For example, the first time the forefathers used contrast it was chalk, and was used on a cadaver's
vessels. Unfortunately, some elements chosen proved to be harmful – for example, thorium was once used as a
contrast medium (Thorotrast) – which turned out to be toxic in some cases (causing injury and occasionally death
from the effects of thorium poisoning). Modern contrast material has improved, and while there is no way to
determine who may have a sensitivity to the contrast, the incidence of "allergic-type reactions" are low. (The risk is
comparable to that associated with penicillin.)


Photostimulable phosphors (PSPs)
An increasingly common method is the use of photostimulated luminescence (PSL), pioneered by Fuji in the 1980s.
In modern hospitals a photostimulable phosphor plate (PSP plate) is used in place of the photographic plate. After
the plate is X-rayed, excited electrons in the phosphor material remain "trapped" in "colour centres" in the crystal
lattice until stimulated by a laser beam passed over the plate surface. The light given off during laser stimulation is
collected by a photomultiplier tube and the resulting signal is converted into a digital image by computer technology,
which gives this process its common name, computed radiography (also referred to as digital radiography). The
PSP plate can be reused, and existing X-ray equipment requires no modification to use them.


Geiger counter
Initially, most common detection methods were based on the ionization of gases, as in the Geiger-Müller counter: a
sealed volume, usually a cylinder, with a mica, polymer or thin metal window contains a gas, a cylindrical cathode
and a wire anode; a high voltage is applied between the cathode and the anode. When an X-ray photon enters the
cylinder, it ionizes the gas and forms ions and electrons. Electrons accelerate toward the anode, in the process
causing further ionization along their trajectory. This process, known as a Townsend avalanche, is detected as a
sudden current, called a "count" or "event".


In order to gain energy spectrum information, a diffracting crystal may be used to first separate the different photons.
The method is called wavelength dispersive X-ray spectroscopy (WDX or WDS). Position-sensitive detectors are
often used in conjunction with dispersive elements. Other detection equipment that is inherently energy-resolving
may be used, such as the aforementioned proportional counters. In either case, use of suitable pulse-processing
(MCA) equipment allows digital spectra to be created for later analysis.


For many applications, counters are not sealed but are constantly fed with purified gas, thus reducing problems of
contamination or gas aging. These are called "flow counters".


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


8




X-ray 5


Scintillators
Some materials such as sodium iodide (NaI) can "convert" an X-ray photon to a visible photon; an electronic
detector can be built by adding a photomultiplier. These detectors are called "scintillators", filmscreens or
"scintillation counters". The main advantage of using these is that an adequate image can be obtained while
subjecting the patient to a much lower dose of X-rays.


Image intensification


X-ray during cholecystectomy


X-rays are also used in "real-time" procedures such as
angiography or contrast studies of the hollow organs
(e.g. barium enema of the small or large intestine)
using fluoroscopy acquired using an X-ray image
intensifier. Angioplasty, medical interventions of the
arterial system, rely heavily on X-ray-sensitive contrast
to identify potentially treatable lesions.


Direct semiconductor detectors
Since the 1970s, new semiconductor detectors have
been developed (silicon or germanium doped with
lithium, Si(Li) or Ge(Li)). X-ray photons are converted
to electron-hole pairs in the semiconductor and are
collected to detect the X-rays. When the temperature is
low enough (the detector is cooled by Peltier effect or
even cooler liquid nitrogen), it is possible to directly determine the X-ray energy spectrum; this method is called
energy dispersive X-ray spectroscopy (EDX or EDS); it is often used in small X-ray fluorescence spectrometers.
These detectors are sometimes called "solid state detectors". Detectors based on cadmium telluride (CdTe) and its
alloy with zinc, cadmium zinc telluride, have an increased sensitivity, which allows lower doses of X-rays to be
used.


Practical application in medical imaging started in the 1990s. Currently amorphous selenium is used in commercial
large area flat panel X-ray detectors for mammography and chest radiography. Current research and development is
focused around pixel detectors, such as CERN's energy resolving Medipix detector.


Note: A standard semiconductor diode, such as a 1N4007, will produce a small amount of current when placed in an
X-ray beam. A test device once used by Medical Imaging Service personnel was a small project box that contained
several diodes of this type in series, which could be connected to an oscilloscope as a quick diagnostic.


Silicon drift detectors (SDDs), produced by conventional semiconductor fabrication, now provide a cost-effective
and high resolving power radiation measurement. Unlike conventional X-ray detectors, such as Si(Li)s, they do not
need to be cooled with liquid nitrogen.


9




X-ray 6


Scintillator plus semiconductor detectors (indirect detection)
With the advent of large semiconductor array detectors it has become possible to design detector systems using a
scintillator screen to convert from X-rays to visible light which is then converted to electrical signals in an array
detector. Indirect Flat Panel Detectors (FPDs) are in widespread use today in medical, dental, veterinary and
industrial applications.


The array technology is a variant on the amorphous silicon TFT arrays used in many flat panel displays, like the ones
in computer laptops. The array consists of a sheet of glass covered with a thin layer of silicon that is in an amorphous
or disordered state. At a microscopic scale, the silicon has been imprinted with millions of transistors arranged in a
highly ordered array, like the grid on a sheet of graph paper. Each of these thin film transistors (TFTs) is attached to
a light-absorbing photodiode making up an individual pixel (picture element). Photons striking the photodiode are
converted into two carriers of electrical charge, called electron-hole pairs. Since the number of charge carriers
produced will vary with the intensity of incoming light photons, an electrical pattern is created that can be swiftly
converted to a voltage and then a digital signal, which is interpreted by a computer to produce a digital image.
Although silicon has outstanding electronic properties, it is not a particularly good absorber of X-ray photons. For
this reason, X-rays first impinge upon scintillators made from e.g. gadolinium oxysulfide or caesium iodide. The
scintillator absorbs the X-rays and converts them into visible light photons that then pass onto the photodiode array.


Visibility to the human eye
While generally considered invisible to the human eye, in special circumstances X-rays can be visible.[19] Brandes,
in an experiment a short time after Röntgen's landmark 1895 paper, reported after dark adaptation and placing his
eye close to an X-ray tube, seeing a faint "blue-gray" glow which seemed to originate within the eye itself.[20] Upon
hearing this, Röntgen reviewed his record books and found he too had seen the effect. When placing an X-ray tube
on the opposite side of a wooden door Röntgen had noted the same blue glow, seeming to emanate from the eye
itself, but thought his observations to be spurious because he only saw the effect when he used one type of tube.
Later he realized that the tube which had created the effect was the only one powerful enough to make the glow
plainly visible and the experiment was thereafter readily repeatable. The knowledge that X-rays are actually faintly
visible to the dark-adapted naked eye has largely been forgotten today; this is probably due to the desire not to repeat
what would now be seen as a recklessly dangerous and potentially harmful experiment with ionizing radiation. It is
not known what exact mechanism in the eye produces the visibility: it could be due to conventional detection
(excitation of rhodopsin molecules in the retina), direct excitation of retinal nerve cells, or secondary detection via,
for instance, X-ray induction of phosphorescence in the eyeball with conventional retinal detection of the secondarily
produced visible light.


Though X-rays are otherwise invisible it is possible to see the ionization of the air molecules if the intensity of the
X-ray beam is high enough. The beamline from the wiggler at the ID11 [21] at ESRF is one example of such high
intensity.[22]


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


10




X-ray 7


Medical uses


X-ray image of the paranasal sinuses,
lateral projection


Head CT scan (transverse plane) slice – a
modern application of X-rays


Since Röntgen's discovery that X-rays can identify bone structures, X-rays
have been developed for their use in medical imaging. Radiology is a
specialized field of medicine. Radiologists employ radiography and other
techniques for diagnostic imaging. This is probably the most common use of
X-ray technology.


X-rays are especially useful in the detection of pathology of the skeletal
system, but are also useful for detecting some disease processes in soft tissue.
Some notable examples are the very common chest X-ray, which can be used
to identify lung diseases such as pneumonia, lung cancer or pulmonary
edema, and the abdominal X-ray, which can detect intestinal obstruction, free
air (from visceral perforations) and free fluid (in ascites). X-rays may also be
used to detect pathology such as gallstones (which are rarely radiopaque) or
kidney stones which are often (but not always) visible. Traditional plain
X-rays are less useful in the imaging of soft tissues such as the brain or
muscle. Imaging alternatives for soft tissues are computed axial tomography
(CAT or CT scanning)[23] , magnetic resonance imaging (MRI) or ultrasound.
The latter two do not subject the individual to ionizing radiation. In addition
to plain X-rays and CT scans, physicians use fluoroscopy as an X-ray test
methodology. This method often uses administration of a medical contrast
material (intravenously, orally or via enema). Examples include cardiac
catheterization (to examine for coronary artery blockages) and Barium
swallow (to examine for esophageal disorders.


Since 2005, X-rays are listed as a carcinogen by the U.S. government.[24] .
The use of X-rays as a treatment is known as radiotherapy and is largely used
for the management (including palliation) of cancer; it requires higher
radiation energies than for imaging alone.


Risks of Medical Diagnostic X-rays
X-rays are a relatively safe method of investigation and the radiation
exposure is relatively low, depending upon the study. Experimental and
epidemiological data, however, do not support the proposition that there is a threshold dose of radiation below which
there is no increased risk of cancer.[25] Diagnostic X-rays account for 14% of the total annual radiation exposure
from man-made and natural sources worldwide.[26] It is estimated that the additional radiation will increase a
person's cumulative risk of getting cancer by age 75 by 0.6-1.8%.[27] The amount of absorbed radiation depends
upon the type of X-ray test and the body part involved.[28] CT and fluoroscopy entail higher doses of radiation than
do plain X-rays.


To place the increased risk in perspective, a plain chest X-ray or dental X-ray will expose a person to the same
amount from background radiation that we are exposed to (depending upon location) everyday over 10 days.[29]


Each such X-ray would add less than 1 per 1,000,000 to the lifetime cancer risk. An abdominal or chest CT would be
the equivalent to 2–3 years of background radiation, increasing the lifetime cancer risk between 1 per 10,000 and 1
per 1,000.[29] These numbers are very small compared to the roughly 40% chance of developing any cancer during
our lifetime.[30]


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


11




X-ray 8


The risk of radiation is greater to unborn babies, so in pregnant patients, the benefits of the investigation (X-ray)
should be balanced with the potential hazards to the unborn fetus.[31] [32] In the US, there are an estimated
62,000,000 CT scans performed annually, including more than 4,000,000 on children.[28] Avoiding unnecessary
X-rays (especially CT scans) will reduce radiation dose and any associated cancer risk.[33]


Shielding against X-Rays
Lead is the most common shield against X-rays because of its high density (11340 kg/m3), stopping power, ease of
installation and low cost. The maximum range of a high-energy photon such as an X-ray in matter is infinite; at
every point in the matter traversed by the photon, there is a probability of interaction. Thus there is a very small
probability of no interaction over very large distances. The shielding of photon beam is therefore exponential (with
an attenuation length being close to the radiation length of the material); doubling the thickness of shielding will
square the shielding effect.


The following table shows the recommended thickness of lead shielding in function of X-ray energy, from the
Recommendations by the Second International Congress of Radiology.[34]


X-Rays generated by peak
voltages


not exceeding


Minimum
thickness
of Lead


75 kV 1.0 mm


100 kV 1.5 mm


125 kV 2.0 mm


150 kV 2.5 mm


175 kV 3.0 mm


200 kV 4.0 mm


225 kV 5.0 mm


300 kV 9.0 mm


400 kV 15.0 mm


500 kV 22.0 mm


600 kV 34.0 mm


900 kV 51.0 mm


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


12




X-ray 14


References
• NASA [53] Goddard Space Flight centre introduction to X-rays.


External links
• An Example of a Radiograph [54]


• A Photograph of an X-ray Machine [55]


• X-ray Safety [56]


• An X-ray tube demonstration (Animation) [57]


• 1896 Article: "On a New Kind of Rays" [58]


• "Digital X-Ray Technologies Project" [59]


• A video of a medical X-ray procedure example [60]


• What is Radiology? [61] a simple tutorial
• 50,000 X-ray, MRI, and CT pictures [62] MedPix medical image database
• Index of Early Bremsstrahlung Articles [63]


References
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15




Article Sources and Contributors 17


Article Sources and Contributors
X- ray  Source: http://en.wikipedia.org/w/index.php?oldid=359644389  Contributors: (jarbarf), 0, 21655, 2D, 2over0, A Softer Answer, A8UDI, ACupOfCoffee, AGToth, Aarchiba, Academic
Challenger, Adam1213, Adambro, Aditya, AdjustShift, Afiller, Agentilini, Ahoerstemeier, Ajraddatz, Alansohn, Aleator, Alesnormales, Alex.tan, Alfio, Alphachimp, Amir hmn2002,
AnakngAraw, Anandgnanaraj, AndKemp, AndonicO, Andrei Stroe, Anonymous Dissident, Antagonist, Antonio Lopez, Anwar saadat, Arakunem, Aribex, Art Carlson, Art LaPella, Ashmoo,
Atif.t2, Average Earthman, AxelBoldt, Axl, Aza, B0at, Baa, Backslash Forwardslash, Badgernet, Baggio10, Bangvang, Barkjon, Bart133, Beetstra, Bemoeial, BenFrantzDale, Bender235,
Benkruisdijk, Bensaccount, Bentu, Bert Hickman, Betacommand, Bhadani, BiT, Bigbear bh, Bige1977, BillC, Binksternet, Blabbyblabby, Blackangel25, Blechnic, BlueDevil, Bobblewik,
Bobjonhson1234567890, Bobmack89x, Bobo192, Bodybagger, Boing! said Zebedee, Bongwarrior, Bouncingmolar, Bowlhover, Bradjamesbrown, Brandon5485, BrendanRyan, BrianOfRugby,
Britney901, Btunell, Bulatyk, Bullzeye, Butane Goddess, Bwilkins, Cairan, Calestyo, Calvin1509, Camw, Can't sleep, clown will eat me, Canadian-Bacon, Capricorn42, Carlj7, Cburnett, Cdang,
Cgmusselman, Chairman S., CharlotteWebb, Chem-awb, ChemNerd, Chetvorno, ChicXulub, Chicago god, Chinju, Chris5858, ChrisGriswold, Ckatz, Clam0p, Clamalosal, Closedmouth, Cls465,
Cohan, Conversion script, Coofjdf, Cool Blue, CorvetteZ51, Cqouliinnn, Craigloomis, Crohnie, CurranH, Cycotic, Cyon, D o z y, DD7990, DHN, DMacks, DV8 2XL, DVD R W, DaL33T,
Daniel5127, DanielCD, Dave souza, Davehi1, David R. Ingham, David.Monniaux, Davidjk, Dazeley, Deglr6328, Dekisugi, Delengar, DerHexer, Digger3000, DimosthenisS, Dirac66, DirkvdM,
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Faithlessthewonderboy, Fang 23, Farahead, Fastfission, FayssalF, Feezo, FelisSchrödingeris, Femto, Ffooxx33, Fieldday-sunday, FireSinger, Flewis, Focus mankind, Foochar, Fordan, Forteblast,
Franetjust, Frostyboy27, Frymaster, Fundistraction, Fvw, Fëaluinix, GHe, Gail, Gaius Cornelius, Garrythefish, Gejigeji, Gene Nygaard, Geneva2007, Giftlite, Gilliam, Glane23, Glyn carter,
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HumphreyW, Huntthetroll, Hydrargyrum, I B Wright, I own in the bed, I.M.S., Icairns, Icarus3, Igoldste, Inkypaws, Insanity Incarnate, Inzy, Ionactive, Iridescent, Irishguy, Irrawaddy, Ixfd64,
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Mdog22, Mentifisto, Merope, Michael Daly, MichaelMouat, Micky bang, Mikalwilliams, Mike Serfas, Mild Bill Hiccup, Milkbreath, Minston, Miquonranger03, MisterDie, Mmxx, Mnolf,
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Perardi, Percy Jackson, PerryS, Peter bertok, Petersam, Pflatau, Phaedriel, Pharaoh of the Wizards, PhilHibbs, Philip Trueman, PhilipBembridge, Philipcosson, Piano non troppo, Pieter Kuiper,
Pigsonthewing, Pince Nez, Pizza Puzzle, Polonium, Pornstar12345, Poupoune5, PrestonH, Princemackenzie, Puchiko, Pyfan, Qrsdogg, Quacha, Quadell, Quandaryus, Quennbee3150, Quintote,
Quixeh, Qwertyus, Qxz, R'n'B, R.J. Croton, RB972, RColbeth, Radon210, Raelx, Ragib, Rapidcreek, RaseaC, RazorICE, Rdsmith4, Rebecca, Rebroad, Reconsider the static, RedLinks, Reddi,
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RoyBoy, Rror, Ruud Koot, Rwmshopping, S Roper, S3000, Salty!, Sam Korn, Samwb123, Savage1881, SchfiftyThree, Scwlong, Seervoitek, Sengkang, Serie, SeteboS, Shaddack, Shadowjams,
Shai-kun, Shalom Yechiel, Shannon bohle, Sherool, Shewlett95, Shizhao, Shmuel Benezra, Shoessss, SimonP, Sjschen, Skier Dude, Skippy le Grand Gourou, Sky Attacker, Skysmith, Sleigh,
Smack, Snottily, Snowolf, Soarhead77, Sodium, Soundray, Spitfire, Srleffler, Stephen Bain, Stephenb, Steve Hart, Stevenfruitsmaak, Stirling Newberry, Stretch 135, Stuart Wimbush, Suh004757,
Suicidalhamster, Sumersethi, SuperHamster, Superbeecat, SusanLesch, Svick, SwirlBoy39, Symane, THEQUEST410, TJ, TMN, Tango, Tarotcards, Tarquin, Tasfhkl, Tawker, Tektoon,
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WereSpielChequers, Werson, Whatever404, Whiner01, White Shadows, Wikibofh, Wikieditor06, Wikipedia brown, William Avery, Wireless Keyboard, Wjbeaty, Wolfkeeper, Wouterstomp,
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Александър, 百 家 姓 之 四 , 1417 anonymous edits


Image Sources, Licenses and Contributors
File:Anna Berthe Roentgen.gif  Source: http://en.wikipedia.org/w/index.php?title=File:Anna_Berthe_Roentgen.gif  License: Public Domain  Contributors: Wilhelm Röntgen
File:Laprascopy-Roentgen.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Laprascopy-Roentgen.jpg  License: Public Domain  Contributors: User:HenrikP
File:X-Ray Skull.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:X-Ray_Skull.jpg  License: Creative Commons Attribution-Sharealike 2.0  Contributors: User:Mnolf
File:Brain CT scan.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Brain_CT_scan.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors: Afiller, Explicit,
Fastily, 2 anonymous edits
File:X-ray diffraction pattern 3clpro.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:X-ray_diffraction_pattern_3clpro.jpg  License: Creative Commons Attribution-Sharealike 3.0
 Contributors: User:Jeff Dahl
File:X-RayOfNeedlefish-1.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:X-RayOfNeedlefish-1.jpg  License: Creative Commons Attribution 3.0  Contributors: Dazeley
File:Roentgen-Roehre.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Roentgen-Roehre.svg  License: Public Domain  Contributors: User:Hmilch
File:Historical X-ray nci-vol-1893-300.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Historical_X-ray_nci-vol-1893-300.jpg  License: Public Domain  Contributors: Unknown
photographer/artist
File:Moon in x-rays.gif  Source: http://en.wikipedia.org/w/index.php?title=File:Moon_in_x-rays.gif  License: unknown  Contributors: Bkell, Deglr6328, Melesse, Skier Dude, Stan Shebs, 2
anonymous edits


License
Creative Commons Attribution-Share Alike 3.0 Unported
http:/ / creativecommons. org/ licenses/ by-sa/ 3. 0/


Wikipedia. “ X-Ray.” Wikipedia, pgs 1-17. Retrieved from: https://en.wikipedia.org/wiki/X-ray


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provided by the AGC, as described above. ABC is used to keep the brightness of the displayed image at a


constant level during examinations. It involves the adjustment of the kV and mA automatically depending on


the part of the anatomy being examined. This can be achieved using a small photosensor at the XII output,


for instance, which monitors the central portion of intensified images and feeds a signal back to the generator


to adjust the kV, the mA (or both) accordingly.


ABC systems are generally designed to operate between minimum (e.g. 70 kV) and maximum (e.g. 120 kV)


kilovoltages. The minimum kV can be used at the start of an exposure sequence, for instance, to prevent low


energy X-rays exposing the patient unnecessary, and is then increased automatically so that a pre-determined


image brightness level is reached. The tube current (mA) can also be adjusted automatically during this


process. Such mA adjustment within the kV range of the ABC is limited by the power rating of the XRT.


When the power limit is reached, in fluoroscopy of the lateral abdomen or at steep-angled cardiac


projections, for instance, further adjustment of exposure factors is no longer possible and the AGC circuitry


can come into play to maintain image brightness. However, images with increased electronic noise generally


result.


The actual kV and mA settings used by ABC systems dictate the contrast displayed in fluoroscopic images


as well as the dose to the patient. A High Dose ABC mode can be used which lowers the kV and boosts


the mA so that image contrast can be improved at the same image brightness, while a Low Dose mode


increases the kV and lowers the mA to effect a similar outcome. A third intermediate mode can also be


selected on many systems. The heat capacity of the XRT imposes the power limit, which is controlled by the


product, (kV x mA), the ABC system automatically applies. This is dictated by the thickness and


composition of the anatomy being screened. When this product reaches the power limit, in the case of a very


large patient, for example, the ABC generally maintains constant kV and mA settings. Hence the need for


additional control provided by the camera's AGC. In addition, the AGC control of image brightness happens


almost instantaneously whereas the HV circuitry can take about a second or so to respond to any ABC


detected illuminance changes. The AGC is therefore also of use during this adaptation period so as to


maintain a constant brightness in displayed images.


Radiation Dose Management


An indicator of the radiation exposure required to generate a CR or DR image is provided on many systems. This


indicator can be called the Sensitivity Index (SI), the Log Median (LgM), the Exposure Index (EI) or similar


parameter and can be used to gauge the adequacy of an exposure. Note that these parameters are generally


referenced to exposures generated under specific conditions, e.g. X-ray energy, beam filtration etc., and therefore


can be regarded only as a crude indicator of patient dose.


Dose-Area Product (DAP) - see the discussion below - records can be used to review exposure trends over time


in the clinical environment


[12]


. One of the aims here is to reduce the phenomenon of Exposure Creep, where


exposures slowly increase over time in the pursuit of images of excellent quality, for example. Another aim here can


be to review exposure measurements relative to Diagnostic Reference Levels (DRLs).


Retake analysis can also be combined with such exposure reviews so that, for instance, a team of X-ray personnel


can work collectively to improve performance. Reasons for retake radiographs can be catalogued into radiographic


exposure errors, including those resulting from patient movement, when too long an exposure is used, for example,


and radiographic positioning errors


[13]


.


Figure 1: X-Ray Tube and Housing


Radiation Dose Man gement


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Skin Injury


There has been considerable interest in recent years in reducing fluoroscopic doses following numerous


reports of epilation and skin injuries to patients from prolonged interventional procedures


[14]


. Regulatory


agencies throughout the world have responded to ICRP deliberations


[15]


and have issued recommendations


to the effect that the person responsible for the apparatus:


Needs to establish standard operating procedures and clinical protocols.


Should know typical radiation dose rates for the specific fluoroscopic system.


Must assess the impact of each procedure's protocol on the potential for radiation injury to


patients.


Must modify the protocol to limit the dose.


Should enlist a qualified health physicist to provide assistance in developing and optimising dose


minimisation techniques.


Should give consideration to rotating the tube and the image intensifier through 180° during


prolonged neuroradiological procedures.


Should give consideration to carrying out those cardiology procedures where multiple stenting is


necessary over a period of weeks to fractionate the radiation dose.


Should give due consideration when purchasing new equipment to features offered by the


manufacturer that may aid in reducing the patient dose.


Skin injury has been found to be sensitive to factors such as previous high dose exposure, medication,


connective tissue disease and diabetes mellitus. A review of hair and skin effects is given in Balter et al.


(2010)


[16]


. Single-site skin doses in interventional radiology above 2 Gy, for example, have been found to


cause erythema and epilation and higher doses to cause permanent skin damage.


Mechanisms of patient dose reduction which have been developed include:


Pulsed Fluoroscopy: this is a feature which uses short pulses of radiation of variable duration


and frequency (Fig. 3.1). Such pulsing can be generated by switching the mA in the HV


generator or by controlling the electron beam of the XRT, as in the Grid-Controlled XRT.


Following each exposure pulse, the image is stored in image memory and displayed


continuously until the next pulse to give a contiguous visual effect. Dose rate reductions of the


order of 90% are achievable using this approach although a stroboscopic artefact may result


when imaging fast moving objects such as the heart.


Additional Filtration: the addition of a thin Cu filter (0.1 - 0.3 mm) at the output of the X-ray


tube can generate substantial dose reductions without a detrimental impact on image quality. A


refinement to this approach is the Region of Interest (ROI) filter which provides little filtration to


the central region of the field of view and substantial filtration in peripheral regions - the


rationale being that high image quality is required in the centre of the field and noisier image data


of lower contrast is tolerable outside of this region for providing general anatomical information


only. This latter mechanism has also been referred to as the X-ray fovea.


Collimation: Since the use of conventional rectangular collimators used with XII-based


fluoroscopy systems (which generate circular images) results in unused exposure, some modern


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systems use circular collimators. These typically have the capability of automatically responding


to changes in source-to-image distance and in the electronic zoom selection used in the XII. A


complex collimator assembly, based on adjustable multileaf absorbers, results and can include


robotic control. Another feature in this regard is referred to as radiation-free collimator


positioning and involves storing an image in computer memory, stopping the exposure and


adjusting the collimator controls so that the computer generates a graphics display of the


collimated region.


Digital Image Storage: the fact that images are stored in computer memory (see the following


chapter) allows the possibility of using features such as Last-Image-Hold (LIH), where the


most recently acquired image is displayed continuously without irradiating the patient,


Reference Imaging, where a previously acquired image is displayed on a second video


monitor for comparison purposes, Image Browsing, where multiple images acquired


previously can be displayed, and Fluoroscopic Loop, where an imaging sequence can be


continuously replayed for closer inspection.


Automatic Brightness Control (ABC) can be used in conjunction with exposure pulse control and additional


filtration to generate what is called Automatic Dose Rate Control (ADRC)


[17]


. Here, different filters can


be selected automatically for insertion into the X-ray beam depending on the particular exposure factors


encountered when screening commences. For example, some ADRC systems can generate the selection of:


a kilovoltage which remains constant during the imaging sequence,


an mA pulse height and width which maintains image brightness, and


the automatic insertion of Cu filters of different thicknesses,


depending of the thickness and composition of the body part being examined. Such systems can be used


with four selectable copper filters, for instance, of thickness 0.2, 0.3, 0.6 and 0.9 mm depending on patient


thickness. Since absorbed doses are greater for larger patient thicknesses, because higher exposure factors


are required to acquire images of adequate brightness, a filter thickness is chosen that hardens the X-ray


beam appropriately and reduces patient dose. This is referred to as Spectral Filtering. The ADRC system


can cause the HV generator to select a constant kV, depending on the Cu filter thickness, and vary the mA


pulse height depending on the anatomy. For example, it may select 60 kV with a 0.9 mm Cu filter for a thin


body part, such as the foot, and 80 kV with a 0.3 Cu filter for a body part greater than 20 cm thick, with the


mA adjusted for each exposure by the generation of pulses of the necessary intensity.


Most fluoroscopy systems also feature an audible alert which sounds after a 'beam-on' time of five minutes.


The accumulated exposure time is generally displayed in real-time on the image display, along with the kV


and mA - and dose rate readings when a Dose-Area Product meter (see below) is installed.


Staff Dose


Three sources of exposure arise for staff when operating radiography and fluoroscopy equipment: the


primary beam used to expose the patient, leakage radiation from the XRT and scattered radiation from the


patient. Lead aprons can be worn and distance exploited to minimise the impact of leakage and scattered


radiation in instances where staff are required to remain in an X-ray room or operating theatre during


exposures. Note however that lead aprons only attenuate X-rays by ~90-95%, depending on their lead


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equivalence. These aprons are generally made from lead-impregnated vinyl, are equivalent to 0.25-0.5 mm


of lead and weigh about 5 kg. Lighter aprons with similar attenuation can be made from composites, such as


tungsten and tin, and may be of value to staff during long interventional procedures. Aprons of 0.5 mm lead


equivalence should be used by staff who remain in close proximity to the patient during exposures. The safer


style is the wrap-around apron, in comparison to backless designs. From a practical perspective, lead


aprons should always be stored vertically on racks since folding them can introduce cracks which reduce


their effectiveness. In addition, they should be radiographed at least annually to check for any such signs of


wear and tear.


In addition, the number of staff in the immediate vicinity of the patient can be kept to a minimum and


warnings given when an exposure is impending. Ideally, staff should be behind a shielded operator's console


area during an exposure. The design of X-ray rooms is such that, in general, adequate shielding and distance


ensures that doses to any person in the room, behind the console or, indeed, external to the room can be


optimised.


In some interventional cases, the interventionist may find it necessary to have their hands in the primary beam


for parts of the procedure. Such repeated exposure over a number of years may potentially lead eventually


to radiation dermatitis of the hands. Dose optimisation in such circumstances can be achieved by arranging


the imaging system so that the hands are kept on the beam exit side of the patient. For example, if the XRT is


positioned under the patient then the hands manipulating the catheter should be on top of the patient.


Fig. 4.15: Typical occupational skin absorbed dose rates near


fixed fluoroscopic equipment in the absence of protective


aprons and drapes: (a) over-couch and (b) under-couch X-ray


tube.


It should also be noted that the use of over-couch XRTs in fluoroscopy can lead to significantly greater staff


doses than systems which use under-couch XRTs - see Figure 4.15. Increased radiation scattered from the


patient and the lack of shielding provided by the structure of the patient table are the cause. An increased


incidence of lens injuries has been found, for instance, in radiologists who have used over-couch systems


without protective screens


[18]


. Note, however, that this over-couch argument may not always be valid when


inverted C-arms are used to assist with hand surgery


[19]


.


The elevated dose rates to the trunk and head of the staff member can be noted in panel (a) of the figure.


Radiation dose to the legs of interventionists can also be significant even with the use of under-couch XRTs -


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Fig. 4.16: Typical isodose curves


(in μGy/min) for a mobile C-arm


fluoroscopy system.


and with C-arm systems


[20][21]


.


The use of C-arm and similar arrangements in cardiac


catheterisation laboratories, operating theatres and angiography


suites can introduce additional hazards - see Figure 4.16. These


arise because of the ergonomics associated with the use of lead


shielding devices - which are intended for the minimisation of scatter


and leakage at the interventionist's position. It is therefore quite


possible for their thyroid and eye lens, for instance, to receive


substantial doses. Thyroid shields and lead spectacles can be worn


and adjustable lead glass shields used for dose optimisation


purposes in these circumstances


[22][23]


. Shielding equivalent to 0.25


mm of lead is generally required with glasses also having side


protection. In addition, interventionists can wear a second


dosemeter at the level of their neck to monitor the dose to their


thyroid and eyes. Note that radiation-associated posterior lens


changes have been observed in the eyes of cardiac Cath Lab staff -


both medical and clinical, most not wearing lead glasses - with an


incidence significantly greater than an unexposed control group


[24]


and that a study of cataract incidence has


been launched for a large sample of interventional cardiologists


[25]


.


The location of the interventionist during the procedure has a large influence on their hand dose


[26]


. A ring


dosemeter on the finger proximal to the XRT can be used to monitor such doses. Lead gloves are not


generally worn for ergonomic reasons and also because the additional attenuation generated when shielded


hands are in the beam will increase the automatically controlled exposure factors. Note that particular


additional optimisation techniques can be required in specialities such as urology


[27]


and endovascular


surgery


[28]


.


Targeted education for all users of specialised X-ray apparatus has been identified as a key optimisation


strategy


[29]


and has been implemented successfully in, for example, computed tomography


[30]


.


Patient Dose


Good imaging geometry should be used to optimise patient protection in radiography, fluoroscopy and


fluorography. In most situations the image receptor should therefore be moved to the maximum distance from


the XRT and the patient placed as close to the image receptor as possible. In other words, the patient should


ideally be moved to the image receptor and not the other way around. Some fluoroscopy systems can do this


automatically so as to maintain a narrow air gap between the patient and image receptor before exposures.


Effective doses to patients from fluoroscopy procedures are considerably higher, as might be expected, than


in General Radiography - see the table below. The higher doses result from both fluoroscopy-screening


exposures and multiple fluorography exposures. Notice that strongly attenuating parts of the body which


contain a number of radio-sensitivite organs, such as the abdomen, generate the larger doses in the table.


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Mean Effective Doses from Fluoroscopy


Procedures


[31][32]


Procedure Effective Dose (mSv)


Cerebral Arteriography 2.5


Nephrostomy 5.5


Barium Meal 8.2


Renal Arteriorography 10.3


Barium Enema 11.7


Biliary Stent Placement 12.5


Enteroclysis 14.0


More recent and extensive data is provided in Mettler et al. (2008)


[33]


. Note that specific patient shielding


can be of benefit to patient dose in different types of X-ray examinations, e.g. thyroid protection in cerebral


angiography


[34]


.


It can be noted from the table that all doses are higher than that of the average annual background dose (2.4


mSv). From this perspective, the dose from a Cerebral Arteriogram is equivalent to about 1 year of


background exposure - its so-called Background Equivalent Radiation Time (BERT). Note however that


considerable variations can exist in patient dosimetric survey data, by a factor of 10 or more, due to patient


anatomical differences and the quality of the imaging technology, for example. Note also that variations by a


factor of over 100 occur in background exposure in different parts of the world. It is apparent that the BERT


is therefore only a very approximate indicator of relative dose.


The higher doses in the above table, and higher still in extended interventional procedures, have prompted


the use of dosimetry equipment to routinely monitor parameters such as the Dose-Area Product (DAP) and


the Peak Skin Dose. DAP (also called the Kerma-Area Product) is a measure of the total energy exiting an


XRT and is generally measured (in Gy cm


2


) at a location in the beam close to the collimators. The parameter


has the advantage that it is independent of source-to-skin distance, as was described previously, and can be


used to estimate stochastic risk from a procedure. The Peak Skin Dose is a useful indicator of the likelihood


of deterministic effects. Such measurements can be also be used to establish a dose scale to assist


interventional staff in radiation dose management


[35]


.


Implementation of dose monitoring is critical for dose optimization in digital radiography. Staff guidelines as


previously developed for film/screen radiography, should include appropriate collimation, source-to-image


distance (SID), focal spot size and patient positioning. This information can also enable effective doses to be


subsequently estimated, in situations where DAP meters, for instance, are not available. The use of image


quality indicators for different examinations is an additional step in assisting clinical management of the


balance between dose and image quality


[36]


.


Results of a comprehensive catalogue of dose surveys from 1980-2007 are summarised in Figure 4.17. It


can be seen that effective dose in General Radiography vary by a factor of >1,000, in the range 0.001 to 3


mSv, depending on the area of anatomy irradiated. Radiography/fluoroscopy procedures, as used for barium


studies, can be seen to generate higher doses (4-8 mSv) as do CT studies (2-16 mSv). Interventional


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Fig. 4.17: Adult effective doses from various X-ray


procedures (adapted from ref. #31).


radiology is seen to generate still higher doses (5-70 mSv). CT and interventional exposures can therefore be


considered at relatively high dose examinations and therefore require greater attention from a dose


management perspective. However, it should be appreciated that these values contain large uncertainties,


which can range by factors of 5-10 or more. Furthermore, the average figures are themselves age- and sex-


averaged and are also subject to a variation of ±40% when referred to an individual patient, depending on


variables which include the patient's weight, orientation, X-ray exposure factors and imaging technology


used. It is therefore apparent that they should be considered as indicative values only which should never be


used as a substitute for the dose to an individual patient from a particular examination. Their use here is solely


to provide a comparison for dose management purposes.


On a final point, note that patient dosimetry in general


radiography, fluoroscopy, mammography and


computed tomography is reviewed in Huda et al.


(2008)


[37]


.


References


1. ↑ Neitzel U, 2005. Status and prospects of digital detector


technology for CR and DR


(http://www.ncbi.nlm.nih.gov/pubmed/15933078) . Radiat


Prot Dosimetry, 114:32-8.


2. ↑ Cowen AR, Davies AG & Kengyelics SM, 2007.


Advances in computed radiography systems and their


physical imaging characteristics


(http://www.ncbi.nlm.nih.gov/pubmed/17981160) . Clin


Radiol, 62:1132-41.


3. ↑ Schaefer-Prokop CM, De Boo DW, Uffmann M & Prokop


M, 2009. DR and CR: Recent advances in technology


(http://www.ncbi.nlm.nih.gov/pubmed/19695809) . Eur J


Radiol, 72:194-201.


4. ↑ Cesar LJ, Schueler BA, Zink FE, Daly TR, Taubel JP &


Jorgenson LL, 2001. Artefacts found in computed


radiography


(http://www.ncbi.nlm.nih.gov/pubmed/11718396) . Br J


Radiol, 74:195-202.


5. ↑ Cowen AR, Davies AG & Sivananthan MU, 2008. The design and imaging characteristics of dynamic, solid-state, flat-


panel x-ray image detectors for digital fluoroscopy and fluorography (http://www.ncbi.nlm.nih.gov/pubmed/18774353) .


Clin Radiol, 63:1073-85.


6. ↑ Cowen AR, Kengyelics SM & Davies AG, 2008. Solid-state, flat-panel, digital radiography detectors and their physical


imaging characteristics (http://www.ncbi.nlm.nih.gov/pubmed/18374710) . Clin Radiol, 63:487-98.


7. ↑ Spahn M, 2005. Flat detectors and their clinical applications (http://www.ncbi.nlm.nih.gov/pubmed/15806363) . Eur


Radiol, 15:1934-47.


8. ↑ Sato K, Nariyuki F, Kuwabara T, Fukui S, Okada Y, Nabeta T, Hosoi Y, Enomoto J, Sasao M & Seguchi Y, 2010.


Development of CALNEO, an indirect-conversion digital radiography system with high-conversion efficiency


(http://www.fujifilm.com/about/research/report/055/pdf/index/ff_rd055_003_en.pdf) . Fujifilm R&D, 55:10-3


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9. ↑ Rivetti S, Lanconelli N, Bertolini M, Borasi G, Golinelli P, Acchiappati D & Gallo E, 2009. Physical and psychophysical


characterization of a novel clinical system for digital mammography (http://www.ncbi.nlm.nih.gov/pubmed/19994524) . Med


Phys, 36:5139-48


10. ↑ Seibert JA, 2006. Flat-panel detectors: How much better are they? (http://www.ncbi.nlm.nih.gov/pubmed/16862412)


Pediatr Radiol, 36 Suppl 2:173-81.


11. ↑ Yaffe MJ & Rowlands JA, 1997. X-ray detectors for digital radiography (http://www.ncbi.nlm.nih.gov/pubmed/9015806) .


Phys Med Biol, 42:1-39.


12. ↑ Schuncke A & Neitzel U, 2005. Retrospective patient dose analysis of a digital radiography system in routine clinical use


(http://www.ncbi.nlm.nih.gov/pubmed/15933094) . Radiat Prot Dosimetry, 114:131-4.


13. ↑ Prieto C, Vano E, Ten JI, Fernandez JM, Iñiguez AI, Arevalo N, Litcheva A, Crespo E, Floriano A & Martinez D, 2009.


Image retake analysis in digital radiography using DICOM header information


(http://www.ncbi.nlm.nih.gov/pubmed/18592314) . J Digit Imaging, 22:393-9.


14. ↑ Shope TS, 1996. Radiation-induced skin injuries from fluoroscopy (http://www.ncbi.nlm.nih.gov/pubmed/8888398) .


Radiographics, 16:1195-9.


15. ↑ Valentin J, 2000. Avoidance of radiation injuries from medical interventional procedures


(http://www.ncbi.nlm.nih.gov/pubmed/11459599) . Ann ICRP, 30:7-67.


16. ↑ Balter S, Hopewell JW, Miller DL, Wagner LK & Zelefsky MJ, 2010. Fluoroscopically guided interventional procedures:


A review of radiation effects on patients' skin and hair (http://www.ncbi.nlm.nih.gov/pubmed/20093507) . Radiology,


254:326-41.


17. ↑ Lin PJ, 2007. The operation logic of automatic dose control of fluoroscopy system in conjunction with spectral shaping


filters (http://www.ncbi.nlm.nih.gov/pubmed/17879779) . Med Phys, 34:3169-72.


18. ↑ Vañó E, González L, Beneytez F & Moreno F, 1998. Lens injuries induced by occupational exposure in non-optimized


interventional radiology laboratories (http://www.ncbi.nlm.nih.gov/pubmed/9771383) . Br J Radiol, 71:728-33.


19. ↑ Tremains MR, Georgiadis GM & Dennis MJ, 2001. Radiation exposure with use of the inverted-c-arm technique in upper-


extremity surgery (http://www.ncbi.nlm.nih.gov/pubmed/11379736) . J Bone Joint Surg Am, 83-A:674-8.


20. ↑ Whitby M & Martin CJ, 2003. Radiation doses to the legs of radiologists performing interventional procedures: Are they


a cause for concern? (http://www.ncbi.nlm.nih.gov/pubmed/12763947) Br J Radiol, 76:321-7.


21. ↑ Shortt CP, Al-Hashimi H, Malone L & Lee MJ, 2007. Staff radiation doses to the lower extremities in interventional


radiology (http://www.ncbi.nlm.nih.gov/pubmed/17533541) . Cardiovasc Intervent Radiol, 30:1206-9.


22. ↑ Shortt CP, Fanning NF, Malone L, Thornton J, Brennan P & Lee MJ, 2007. Thyroid dose during neurointerventional


procedures: Does lead shielding reduce the dose? (http://www.ncbi.nlm.nih.gov/pubmed/17533529) Cardiovasc Intervent


Radiol, 30:922-7.


23. ↑ Thornton RH, Dauer LT, Altamirano JP, Alvarado KJ, St Germain J & Solomon SB, 2010. Comparing strategies for


operator eye protection in the interventional radiology suite (http://www.ncbi.nlm.nih.gov/pubmed/20920841) . J Vasc


Interv Radiol, 21:1703-7.


24. ↑ Vano E, Kleiman NJ, Duran A, Rehani MM, Echeverri D & Cabrera M, 2010. Radiation cataract risk in interventional


cardiology personnel (http://www.ncbi.nlm.nih.gov/pubmed/20726724) . Radiat Res, 174:490-5.


25. ↑ Jacob S, Michel M, Spaulding C, Boveda S, Bar O, Brézin AP, Streho M, Maccia C, Scanff P, Laurier D & Bernier MO,


2010. Occupational cataracts and lens opacities in interventional cardiology (O'CLOC study): Are X-Rays involved?


Radiation-induced cataracts and lens opacities (http://www.ncbi.nlm.nih.gov/pubmed/20825640) . BMC Public Health,


10:537.


26. ↑ Martin CJ, 2009. A review of radiology staff doses and dose monitoring requirements


(http://www.ncbi.nlm.nih.gov/pubmed/19759087) . Radiat Prot Dosimetry, 136:140-57.


27. ↑ Hellawell GO, Mutch SJ, Thevendran G, Wells E & Morgan RJ, 2005. Radiation exposure and the urologist: What are the


risks? (http://www.ncbi.nlm.nih.gov/pubmed/16094003) J Urol, 174:948-52.


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28. ↑ Walsh SR, Cousins C, Tang TY, Gaunt ME & Boyle JR, 2010. Ionizing radiation in endovascular interventions


(http://www.ncbi.nlm.nih.gov/pubmed/19090630) . J Endovasc Ther, 15:680-7.


29. ↑ Le Heron J, Padovani R, Smith I & Czarwinski R, 2010. Radiation protection of medical staff


(http://www.ncbi.nlm.nih.gov/pubmed/20656429) . Eur J Radiol. 2010 Oct;76(1):20-3.


30. ↑ Wallace AB, Goergen SK, Schick D, Soblusky T & Jolley D, 2010. Multidetector CT dose: Clinical practice improvement


strategies from a successful optimization program (http://www.ncbi.nlm.nih.gov/pubmed/20678731) . J Am Coll Radiol,


7:614-24.


31. ↑ Ruiz-Cruces R, Perez-Martinez M, Martin-Palanca, Flores A, Cristófol J, Martínez-Morillo M & Díez de los Ríos A, 1997.


Patient dose in radiologically guided interventional vascular procedures: Conventional versus digital systems


(http://www.ncbi.nlm.nih.gov/pubmed/9356618) . Radiology, 205:385-93.


32. ↑ Ruiz-Cruces R, Ruiz F, Pérez-Martínez M, López J, Tort Ausina I & de los Ríos AD, 2000. Patient dose from barium


procedures (http://www.ncbi.nlm.nih.gov/pubmed/11089468) . Br J Radiol, 73:752-61.


33. ↑ Mettler FA Jr, Huda W, Yoshizumi TT & Mahesh M, 2008. Effective doses in radiology and diagnostic nuclear medicine:


A catalog (http://www.ncbi.nlm.nih.gov/pubmed/18566177) . Radiology, 248:254-63.


34. ↑ Shortt CP, Malone L, Thornton J, Brennan P & Lee MJ, 2008. Radiation protection to the eye and thyroid during


diagnostic cerebral angiography: A phantom study (http://www.ncbi.nlm.nih.gov/pubmed/18811760) . J Med Imaging


Radiat Oncol, 52:365-9.


35. ↑ Davies AG, Cowen AR, Kengyelics SM, Moore J, Pepper C, Cowan C & Sivanathan MU, 2006. X-ray dose reduction in


fluoroscopically guided electro-physiology procedures (http://www.ncbi.nlm.nih.gov/pubmed/16606393) . Pacing Clin


Electrophysiol, 29:262-71.


36. ↑ Uffmann M & Schaefer-Prokop C, 2009. Digital radiography: The balance between image quality and required radiation


dose (http://www.ncbi.nlm.nih.gov/pubmed/19628349) . Eur J Radiol, 72:202-8.


37. ↑ Huda W, Nickoloff EL & Boone JM, 2008. Overview of patient dosimetry in diagnostic radiology in the USA for the past


50 years (http://www.ncbi.nlm.nih.gov/pubmed/19175129) . Med Phys, 35:5713-28.


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25




Operation and Use of X-Ray Systems


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


26




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


27




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


28




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


29




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


30




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


31




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


32




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


33




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


34




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


35




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


36




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


37




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


38




WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


39




2.*Diagrams*and*Schematics*of*XCRay*Systems****Featured*in*this*Section:****Dilmen,&N.&“Medical&X"Ray&Imaging&ALPo2.”&Wikimedia(Commons,&November&12,&2011.&Retrieved&from:&https://commons.wikimedia.org/wiki/File:Medical_X"Ray_imaging_ALP02_nevit.jpg&&&& McClelland,&I.&R.&“Appendix&E:&X"Ray&Equipment&Operation.”&From&the&Publication:&XARay(Equipment(Maintenance(and(Repairs(Workbook(for(Radiographers(&(Radiological(Technologists,&(WHO:&2004).&& *WHO.&“Stationary&Basic&Diagnostic&X"Ray&System,&Digital.”&From&the&publication:&“WHO&Technical&Specifications&for&61&Medical&Devices.&WHO.&Retrieved&from:&http://www.who.int/medical_devices/management_use/mde_tech_spec/en/&&&WHO.&“Stationary&Basic&Diagnostic&X"Ray&System,&Analogue.”&From&the&publication:&“WHO&Technical&Specifications&for&61&Medical&Devices.&WHO.&Retrieved&from:&http://www.who.int/medical_devices/management_use/mde_tech_spec/en/&


40




APPENDIX E. X-RAY EQUIPMENT OPERATION
209


T U ~ ~ housing is ~ i i fi l led. X-ray t u b e a n d hous ing .
This provider h igh voltage


insuiotion, a n d conducts X-ray
h e o i f rom the X-ray tube


o n d staior \ tube- /;"tb",k:' winding


Bellows. Allows
when heated


T h e r m o safety


h e o i sensor)


Anode Support


Cathode
Receptacle


L A " , , ,
Receptacle


Fig E-9. The X-ray tube and housing


X-ray tube anode


X-ray tube cathode W


d
Actual focal spot


Filament inside
focus cup n


Change of effective foca l spot
owoy from peipendiculor t o the
onode


The width 'W' depends on
the f i lament d iameter and
design of the focal cup.


Cathode Anode 1 1
Projecied focal spot


Fig E-10. Formation of the focal spot


e. Anode angle 100
-


+ 80 The wider the anode angle, the greater will be the film
coverage at a spec~f~c distance. However, to maintain P 60


0 the same focal spot size, the length 'l' of the electron 40
beam must be reduced.This results in a smaller area $ 20 to dissipate the immediate heat, so the maximum x
output of the tube has to be reduced. See Fig E-10. r r O 20 1 6 12 8 4 4 8 12 1 6 20


A common angle for an over-table tube is 12? An t Anode Cathode- Radiat ion centre
under-table tube in a fluoroscopy table may have an
angle of 16g.With a 12F: angle, rad~ation may cover a Fig E-l I . Relative radiation output for two anode angles
35 x 35cm film at a FFD of 100cm,while a 16O lngle


Figure 1: X-Ray Tube and Housing


41




Figure 2: Example of an X-Ray


Dilmen, N. “Medical X-Ray Imaging ALPo2.” Wikimedia Commons, November 12, 2011. Retrieved from: https://


commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_ALP02_nevit.jpg


42




11/18/15 WHO_TS_61_MDs_web.xlsx 50


Page 1


i Version No. 1ii Date of initial version 6/13/12iii Date of last modification 6/18/14iv Date of publicationv Completed / submitted by WHO working group1 WHO Category / Code (under development)2 Generic name X-Ray Imaging System3 Specific type or variation (optional) fixed, analogue4 GMDN name Stationary basic diagnostic x-ray system, analogue5 GMDN code 376446 GMDN category 12 Diagnostic and therapeutic radiation devices7 UMDNS name Radiographic/Fluoroscopic Systems, General-Purpose 8 UMDNS code 168859 UNSPS code (optional)10 Alternative name/s (optional) Basic radiologic system (BRS); General radiographic x-ray equipment; Radiographic unit, chest; Radiographic unit, general-purpose; Paediatric radiographic unit; Radiographic unit, skeletal11 Alternative code/s (optional) MS 17153; MS 34239; MS 10822; MS 13271; MS 36119; MS 1655712 Keywords (optional) imaging, radiology, film13
GMDN/UMDNS definition (optional)


An assembly of devices that comprise a general-purpose stationary diagnostic x-ray system used in a variety of routine planar x-ray imaging applications. It is typically an x-ray film based system that use analogue or analogue-to-digital techniques for image capture and display. The stationary design requires it to be installed and used in a fixed location within a building or in a transportation van (mobile imaging facility). This system consists of modular configurations that can be upgraded by the addition of hardware/software components or accessories. This generic device group does not cover systems with fluoroscopic or tomographic capabilities.
14 Clinical or other purpose An assembly of devices that comprise a general-purpose stationary diagnostic x-ray system used in a variety of routine planar x-ray imaging applications. 15 Level of use (if relevant) Health post, health centre, district hospital, provincial hospital, specialized hospital, radiology practice16 Clinical department/ward(if relevant) Radiology department, Orthopaedics, Emergency room17 Overview of functional requirements 1. Provides X-ray film images of all body parts except for brain.2. X ray generator and cassette holder can be moved to image body part of interest.3. X-ray generator, bucky and patient table movable to enable comfortable and precise imaging. 4. Separate control console (behind protective screens).5. Fluoroscopic capacity is not required.


MEDICAL DEVICE SPECIFICATION(Including information on the following where relevant/appropriate, but not limited to)
NAME, CATEGORY AND CODING


PURPOSE OF USE


TECHNICAL CHARACTERISTICS


Figure 3: WHO Specification Analog Diagnostic X-Ray


WHO. “Stationary Basic Diagnostic X-Ray System, Analogue.” From the publication: “WHO Technical Specifications for 61


Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/management_use/mde_tech_spec/en/


43




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Page 2


18 Detailed requirements 1. Must have a digital display of mAs and kV, and an electronic timer. 2. kV range at least 50 kV to 150 kV, digitally displayed.3. mA range at least 0 to 600 mA.4. Exposure time range at least 1 ms to 5 s.5. Automatic exposure control facility required.6. Tube power rating at least 60 kW.7. Resolution to be better than 5 line pairs / mm.8. Must have a rotating anode with focal spot size less than 1mm. 9. Heat storage capacity of the anode at least 350,000 HU.10. Adjustable multileaf collimator, rotatable ±90 deg with patient centering light.
19 Displayed parameters N/A20 User adjustable settings N/A
21 Components(if relevant) 1. Patient table to have motorized tilt from at least +90 deg to -15 deg.2. All cables on the patient table unit should be concealed.3. Patient table longitudinal and lateral movements to be at least 160 cm and 20 cm respectively.4. Patient table vertical movement to include the range 60 cm to 120 cm from ground.5. X-ray head longitudinal, vertical and lateral patient movement to be at least 100 cm, 30 cm and 20 cm respectively.6. Source to image distance should at least include the range 90 cm to 125 cm.7. The tube head must be fully counterbalanced for safe and easy movement.8. Maximum possible patient weight to be at least 150 kg.9. Dust cover for control unit to be supplied.10. Protection against insect and rodent ingress to be incorporated.22 Mobility, portability(if relevant)23 Raw Materials(if relevant)24 Electrical, water and/or gas supply (if relevant) 1. Power input to be ******** fitted with ******* compatible mains plug, if single phase.2. Power input to be ******* fitted with secure connection to supply, if three phase.3. Voltage corrector / stabilizer to allow operation at ± 30% of local rated voltage.4. Electrical protection by resettable overcurrent breakers or replaceable fuses, fitted in both live and neutral lines.5. Mains cable to be at least 3m length.
25 Accessories (if relevant) 1. To be supplied with two adult size protective lead aprons.2. Supplier to specify full range of grids available.3. Radiation hazard warning signs to be supplied with unit.26 Sterilization process for accessories (if relevant) N/A27 Consumables / reagents (if relevant) N/A28 Spare parts (if relevant) N/A29 Other components (if relevant)N/A30 Sterility status on delivery (if relevant) N/A31 Shelf life (if relevant) N/A


ACCESSORIES, CONSUMABLES, SPARE PARTS, OTHER COMPONENTS


PACKAGING


UTILITY REQUIREMENTS


PHYSICAL/CHEMICAL CHARACTERISTICS


WHO. “Stationary Basic Diagnostic X-Ray System, Analogue.” From the publication: “WHO Technical Specifications for 61


Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/management_use/mde_tech_spec/en/


44




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Page 3


32 Transportation and storage (if relevant) N/A33 Labelling (if relevant) N/A34 Context-dependent requirements 1. Capable of being stored continuously in ambient temperature of 0 to 50 deg C and relative humidity of 15 to 90%.2. Capable of operating continuously in ambient temperature of 10 to 40 deg C and relative humidity of 15 to 90%.
35 Pre-installation requirements(if relevant) Supplier to perform installation, safety and operation checks before handover. Supplier to clearly state supply current requirements of unit.36 Requirements for commissioning (if relevant) Local clinical staff to affirm completion of installation.37 Training of user/s (if relevant) Training of users in operation and basic maintenance shall be provided38 User care(if relevant) Unit layout to enable easy cleaning and sterilization of all surfaces.39 Warranty 1 year40 Maintenance tasks Preventive/periodic maintenance requirements to be listed. 41 Type of service contract N/A42 Spare parts availability post-warranty N/A43 Software / Hardware upgrade availability N/A44 Documentation requirements 1. User, technical and maintenance manuals to be supplied in (***** language).2. List to be provided of equipment and procedures required for local calibration and routine maintenance.3. List to be provided of important spares and accessories, with their part numbers and cost. 4. Certificate of calibration and inspection to be provided.5. Contact details of manufacturer, supplier and local service agent to be provided.
45 Estimated Life Span 5 years46 Risk Classification Class C (GHTF Rule 10 (ii)); Class II (USA); Class II b (EU and Australia); Class II (Japan and Canada)47 Regulatory Approval / Certification FDA approval (USA); CE mark (EU)


DECOMMISSIONINGSAFETY AND STANDARDS


ENVIRONMENTAL REQUIREMENTS
TRAINING, INSTALLATION AND UTILISATION


WARRANTY AND MAINTENANCE


DOCUMENTATION


WHO. “Stationary Basic Diagnostic X-Ray System, Analogue.” From the publication: “WHO Technical Specifications for 61


Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/management_use/mde_tech_spec/en/


45




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Page 4


48 International standards ISO 13485:2003 Medical devices -- Quality management systems -- Requirements for regulatory purposes (Australia, Canada and EU)ISO 14971:2007 Medical devices -- Application of risk management to medical devicesIEC 60601-1:2012 Medical electrical equipment - Part 1: General requirements for basic safety and essential performanceIEC 60601-1-1:2000 Medical electrical equipment - Part 1-1: General requirements for safety - Collateral standard: Safety requirements for medical electrical systemsIEC 60601-1-2:2007 Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirements and testsIEC 60336:2005 (X-ray tube assemblies for medical diagnosis - Characteristics of focal spots)IEC 60522:1999 (Determination of the permanent filtration of X-ray tube assemblies)IEC 60526:1978 (High-voltage cable plug and socket connections for medical X-ray equipment)IEC 60601-1-3:2013 (Part 1-3: General requirements for basic safety and essential performance - Collateral Standard: Radiation protection in diagnostic X-ray equipment)IEC 60601-2-8:2010 (Part 2-8: Particular requirements for basic safety and essential performance of therapeutic X-ray equipment operating in the range 10 kV to 1 MV)IEC 60601-2-28:2010 (Part 2-28: Particular requirements for the basic safety and essential performance of X-ray tube assemblies for medical diagnosis)IEC 60601-2-43:2010 (Part 2-43: Particular requirements for the basic safety and essential performance of X-ray equipment for interventional procedures)IEC 60601-2-54:2009 (Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment for radiography and radioscopy)IEC 60613:2010 (Electrical and loading characteristics of X-ray tube assemblies for medical diagnosis)IEC 60627:2013 Diagnostic X-ray imaging equipment - Characteristics of general purpose and mammographic anti-scatter grids)IEC 61262-1:1994 (Part 1: Determination of the entrance field size)IEC 61262-2:1994 (Part 2: Determination of the conversion factor)IEC 61262-3:1994 (Part 3: Determination of the luminance distribution and luminance non-uniformity)IEC 61262-4:1994 (Part 4: Determination of the image distortion)IEC 61262-5:1994 (Part 5: Determination of the detective quantum efficiency)IEC 61262-6:1994 (Part 6: Determination of the contrast ratio and veiling glare index)IEC 61262-7:1995 (Part 7: Determination of the modulation transfer function)IEC 61267:2005 (Medical diagnostic X-ray equipment - Radiation conditions for use in the determination of characteristics)IEC 61676:2009 (Medical electrical equipment - Dosimetric instruments used for non-invasive measurement of X-ray tube voltage in diagnostic radiology)(IEC 62463:2010 Radiation protection instrumentation - X-ray systems for the screening of persons for security and the carrying of illicit items)49 Reginal / Local Standards US standardsNEMA XR7-1995 (R2000) High-Voltage X-Ray Cable Assemblies and Receptacles EU standardsEN 60522:1999 Determination of the permanent filtration of X-ray tube assemblies EN 60601-2-8:1997 Medical electrical equipment - Part 2: Particular requirements for the safety of therapeutic X-ray equipment operating in the range 10 kV to 1 MV EN 60601-2-28:1993 Medical electrical equipment - Part 2: Particular requirements for the safety of X-ray source assemblies and X-ray tube assemblies for medical diagnosis EN 60601-2-28:2010 Medical electrical equipment - Part 2-28: Particular requirements for the basic safety and essential performance of X-ray tube assemblies for medical diagnosis EN 60601-2-43:2010 Medical electrical equipment - Part 2-43: Particular requirements for basic safety and essential performance of X-ray equipment for interventional procedures EN 60601-2-54:2009 Medical electrical equipment - Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment for radiography and radioscopy EN 61676:2002 Medical electrical equipment - Dosimetric instruments used for non-invasive measurement of X-ray tube voltage in diagnostic radiology EN 62220-1:2004 Medical electrical equipment - Characteristics of digital X- ray imaging devices - Part 1: Determination of the detective quantum efficiency Japan standardsJIS Z 4751-2-28:2008 (Part 2-28: Particular requirements for the safety of X-ray source assemblies and X-ray tube assemblies for medical diagnosis) JIS Z 4751-2-54:2012 (Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment for radiography and radioscopy)


46




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50 Regulations US regulations21 CFR part 82021CFR part 892.1680 Stationary x-ray systemEU regulationsCouncil Directive 93/42/EEC Directive 93/68/EEC (CE Marking)Directive 98/79/ECDirective 2001/104/EC Directive 2007/47/ECJapan regulationsMHLW Ordinance No.16937644010 Stationary analogue general-purpose diagnostic X-ray system37644020 Stationary analogue general-purpose integral diagnostic X-ray system


WHO. “Stationary Basic Diagnostic X-Ray System, Analogue.” From the publication: “WHO Technical Specifications for 61


Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/management_use/mde_tech_spec/en/


47




WHO_TS_61_MDs_web.xlsx 51


1


i Version No. 1ii Date of initial version 6/13/12iii Date of last modification 6/18/14iv Date of publicationv Completed / submitted by WHO working group1 WHO Category / Code (under development)2 Generic name X-ray system3 Specific type or variation (optional) stationary, digital4 GMDN name Stationary basic diagnostic x-ray system, digital5 GMDN code 376456 GMDN category 12 Diagnostic and therapeutic radiation devices7 UMDNS name Radiographic/Fluoroscopic Systems, General-Purpose 8 UMDNS code 16-8859 UNSPS code (optional)10 Alternative name/s (optional) Basic radiologic system (BRS); Digital radiography; Electronically recorded digital radiography; General radiographic x-ray equipment; Radiographic unit, chest; Radiographic unit, general-purpose; Paediatric radiographic unit; Radiographic unit, skeletal11 Alternative code/s (optional) MS 17153; MS 34281; MS 34283; MS 34239; MS 10822; MS 13271; MS 36119; MS 1655712 Keywords (optional) imaging, radiology
13 GMDN/UMDNS definition (optional)


An assembly of devices that comprise general-purpose stationary diagnostic x-ray system used in a variety of routine planar x-ray imaging applications. It uses digital techniques for image capture, display and manipulation. The stationary design requires it to be installed and used in a fixed location within a building or in a transportation van (a mobile imaging van). This system consists of modular configurations that can be upgraded by the addition of hardware/software components. This GMDN code does not cover systems with fluoroscopic or tomographic capabilities.
14 Clinical or other purpose Designed for use in the laboratory for temperatures over a wide or particular range15 Level of use (if relevant) Health center, district hospital, provincial hospital, specialized hospital16 Clinical department/ward(if relevant)
17 Overview of functional requirements Provides X-ray film images of all parts of the bodyX ray generator and image intensifier can be moved to image required body partControl unit to be separate for operation from behind protective screensDICOM compatible image storage and transfer requiredFluoroscopic capacity is not required


18
Detailed requirements Must have a digital display of mAs and kV, and an electronic timer. kV range at least 50kV to 150kV, digitally displayedmA range at least 0 to 600 mAExposure time range at least 1 ms to 5 sAutomatic exposure control facility requiredTube power rating at least 60 kW Resolution to be better than 5 line pairs / mmMust have a rotating anode with focal spot size less than 1mm. Heat storage capacity of the anode at least 350,000 HUAdjustable multileaf collimator, rotatable ±90 deg with patient centering light Alphanumeric annotation of images requiredImage display to be contrast- and brightness- adjustable, at least 18 inches diagonal sizeImage to be displayed immediately after exposureThe system should be capable of storing at least 3000 images, with capacity for removable media storage19 Displayed parameters20 User adjustable settings


MEDICAL DEVICE SPECIFICATION
NAME, CATEGORY AND CODING


PURPOSE OF USE


TECHNICAL CHARACTERISTICS


Figure 4: WHO Specification Digital Diagnostic X-Ray


WHO. “Stationary Basic Diagnostic X-Ray System, Digital.” From the publication: “WHO Technical


Specifications for 61 Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/


management_use/mde_tech_spec/en/


48




WHO_TS_61_MDs_web.xlsx 51


2


21
Components(if relevant) Patient table to have motorized tilt from + 90 deg to - 15 deg at leastAll cables on the patient table unit should be concealed in the systemPatient table longitudinal and lateral movements to be at least 160 cm and 20 cm respectivelyPatient table vertical movement to include the range 60 cm to 120 cm from groundX-ray generator longitudinal, vertical and lateral movement to be at least 100 cm, 30 cm and 20 cm respectivelySource to image distance should at least include the range 90 cm to 125 cmThe tube head must be fully counterbalanced for safe and easy movementMaximum possible patient weight to be at least 150 kgDust cover for control unit to be suppliedProtection against insect and rodent ingress to be incorporated22 Mobility, portability(if relevant)23 Raw Materials(if relevant)


24 Electrical, water and/or gas supply (if relevant) Power input to be ************* fitted with ********** compatible mains plug, if single phasePower input to be ************* fitted with secure connection to supply, if three phaseVoltage corrector / stabilizer to allow operation at ± 30% of local rated voltage.Electrical protection by resettable overcurrent breakers, fitted in both live and neutral linesMains cable to be at least 3m length, if single phase
25 Accessories (if relevant) To be supplied with two adult size protective lead apronsRadiation hazard warning signs to be supplied with unit 26 Sterilization process for accessories (if relevant)27 Consumables / reagents (if relevant)28 Spare parts (if relevant)29 Other components (if relevant)
30 Sterility status on delivery (if relevant) N/A31 Shelf life (if relevant) N/A32 Transportation and storage (if relevant) N/A33 Labelling (if relevant) N/A
34 Context-dependent requirements Capable of being stored continuously in ambient temperature of 0 to 50 deg C and relative humidity of 15 to 90%.Capable of operating continuously in ambient temperature of 10 to 40 deg C and relative humidity of 15 to 90%.
35 Pre-installation requirements(if relevant) Supplier to perform installation, safety and operation checks before handover.Supplier to clearly state supply current requirements of unit36 Requirements for commissioning (if relevant)37 Training of user/s (if relevant) Training of users in operation and basic maintenance shall be provided38 User care(if relevant) Unit layout to enable easy cleaning and sterilization of all surfaces39 Warranty40 Maintenance tasks Advanced maintenance tasks required shall be documented41 Type of service contract Local clinical staff to affirm completion of installation42 Spare parts availability post-warranty43 Software / Hardware upgrade availabilityDOCUMENTATION


UTILITY REQUIREMENTS
ACCESSORIES, CONSUMABLES, SPARE PARTS, OTHER COMPONENTS


PACKAGING
ENVIRONMENTAL REQUIREMENTS
TRAINING, INSTALLATION AND UTILISATION


WARRANTY AND MAINTENANCE


PHYSICAL/CHEMICAL CHARACTERISTICS


WHO. “Stationary Basic Diagnostic X-Ray System, Digital.” From the publication: “WHO Technical


Specifications for 61 Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/


management_use/mde_tech_spec/en/


49




WHO_TS_61_MDs_web.xlsx 51


3


44 Documentation requirements User, technical and maintenance manuals to be supplied in ************** language.List to be provided of equipment and procedures required for local calibration and routine maintenanceList to be provided of important spares and accessories, with their part numbers and cost. Certificate of calibration and inspection to be provided.Contact details of manufacturer, supplier and local service agent to be provided45 Estimated Life Span 5 to 10 years46 Risk Classification Class C (GHTF Rule 10(ii));Class II (USA); Class II (EU, Japan, Canada and Australia)47 Regulatory Approval / Certification Must be FDA, CE or UL approved product.


48


International standards ISO 13485:2003 Medical devices -- Quality management systems -- Requirements for regulatory purposes (Australia, Canada and EU)ISO 14971:2007 Medical devices -- Application of risk management to medical devices IEC 60601-1:2012 Medical electrical equipment - Part 1: General requirements for basic safety and essential performanceIEC 60601-1-1:2000 Medical electrical equipment - Part 1-1: General requirements for safety - Collateral standard: Safety requirements for medical electrical systemsIEC 60601-1-2:2007 Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirements and tests IEC 60336:2005 (X-ray tube assemblies for medical diagnosis - Characteristics of focal spots)IEC 60522:1999 (Determination of the permanent filtration of X-ray tube assemblies)IEC 60526:1978 (High-voltage cable plug and socket connections for medical X-ray equipment)IEC 60601-1-3:2013 (Part 1-3: General requirements for basic safety and essential performance - Collateral Standard:Radiation protection in diagnostic X-ray equipment)IEC 60601-2-8:2010 (Part 2-8: Particular requirements for basic safety and essential performance of therapeutic X-ray equipment operating in the range 10 kV to 1 MV)IEC 60601-2-28:2010 (Part 2-28: Particular requirements for the basic safety and essential performance of X-ray tube assemblies for medical diagnosis)IEC 60601-2-43:2010 (Part 2-43: Particular requirements for the basic safety and essential performance of X-ray equipment for interventional procedures)IEC 60601-2-54:2009 (Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment for radiography and radioscopy)IEC 60613:2010 (Electrical and loading characteristics of X-ray tube assemblies for medical diagnosis)IEC 60627:2013 Diagnostic X-ray imaging equipment - Characteristics of general purpose and mammographic anti-scatter grids)IEC 61262-1:1994 (Part 1: Determination of the entrance field size)IEC 61262-2:1994 (Part 2: Determination of the conversion factor)IEC 61262-3:1994 (Part 3: Determination of the luminance distribution and luminance non-uniformity)IEC 61262-4:1994 (Part 4: Determination of the image distortion)IEC 61262-5:1994 (Part 5: Determination of the detective quantum efficiency)IEC 61262-6:1994 (Part 6: Determination of the contrast ratio and veiling glare index)IEC 61262-7:1995 (Part 7: Determination of the modulation transfer function)IEC 61267:2005 (Medical diagnostic X-ray equipment - Radiation conditions for use in the determination of characteristics)IEC 61676:2009 (Medical electrical equipment - Dosimetric instruments used for non-invasive measurement of X-ray tube voltage in diagnostic radiology)IEC 62463:2010 Radiation protection instrumentation - X-ray systems for the screening of persons for security and the carrying of illicit items)
49 Reginal / Local Standards JIS Z 4751-2-28:2008 (Part 2-28: Particular requirements for the safety of X-ray source assemblies and X-ray tube assemblies for medical diagnosis)JIS Z 4751-2-54:2012 (Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment for radiography and radioscopy)NEMA XR7-1995 (R2000) High-Voltage X-Ray Cable Assemblies and Receptacles
50 Regulations US regulations 21 CFR part 820 21CFR part 892.1680 Stationary x-ray system JP regulations MHLW Ordinance No.169 37645010 Stationary digital general-purpose diagnostic X-ray system37645020 Stationary digital general-purpose integral diagnostic X-ray system


DECOMMISSIONINGSAFETY AND STANDARDS


WHO. “Stationary Basic Diagnostic X-Ray System, Digital.” From the publication: “WHO Technical


Specifications for 61 Medical Devices. WHO. Retrieved from: http://www.who.int/medical_devices/


management_use/mde_tech_spec/en/


50




&& & 3.*Preventative*Maintenance*of*XCRay*Systems****Featured*in*this*Section:*****Engineering&World&Health.&“Preventative&Maintenance&Schedule&for&X"Ray&Viewer.&EWH.&2012.(*McClelland,&I.&R.&“Appendix&E:&X"Ray&Equipment&Operation.”&From&the&Publication:&XARay(Equipment(Maintenance(and(Repairs(Workbook(for(Radiographers(&(Radiological(Technologists,&(WHO:&2004).&&*Strengthening&Specialised&Clinical&Services&in&the&Pacific.&User(Care(of(Medical(Equipment:(A(first(line(maintenance(guide(for(end(users.&(2015).& * *


51




User Care of Medical Equipment – First line maintenance for end users


74


User Care Checklist – X-Ray Machines


Daily

Cleaning




9 Clean dust from the unit with a dry cloth

9 Remove any tape, paper or foreign body from equipment





Visual checks




9 Check all parts are present and connected


9 Check cables are not twisted and remove from service if any
damage is visible




Function
checks




9 Switch on power and check all indicators function




Weekly

Cleaning




9 Clean all dust and dirt from the X-Ray machine and room



Visual checks




9 If any plug, cable or socket is damaged, refer to biomedical
technician




9 Check all knobs, switches and wheels operate properly


9 Check lead aprons for any defects


9 Check table, cassette holder and grids for smooth movement



Function check




9 If machine has not been in use, wear lead apron and check
whether exposure indicator lights on switch operation




9 Check collimator bulb, replace with correct type if needed




Every six months
Biomedical Technician check required




Strengthening Specialised Clinical Services in the Pacific. User Care of Medical Equipment: A first line maintenance guide for end users.


(2015).


X-Ray Preventative Maintenance Checklist


52




!Preventative)Maintenance)for)X/ray)viewer)(Illuminator,)Radiographic)View)Box)) Inspect!exterior!of!equipment!for!damage!or!missing!hardware.!! Inspect!the!power!cord,!strain!relief!and!plug/s!for!any!signs!of!damage.!! Turn!unit!off,!open!user!accessible!covers!and!inspect!unit!for!damage.! Clean!unit!interior!components!and!exterior!with!vacuum!or!compressed!air.! Inspect!interior!for!signs!of!corrosion!or!missing!hardware.!Repair!as!required.! Inspect!electrical!components!for!signs!of!excessive!heat!or!deterioration.!!! Inspect/adjust!film!holders!and!film!activated!switches!as!required.! Verify!adequate!minimum!illumination!in!all!banks.! Verify!correct!operation!of!safety!interlocks.!! Verify!correct!operation!of!all!buttons,!controls,!displays!and/or!indicators.!!!!!!


Preventative Maintenance for X-Ray Viewers


Engineering World Health. “Preventative Maintenance Schedule for X-Ray Viewer. EWH. 2012.


53




APPENDIX E. X-RAY EQUIPMENT OPERATION
23 1


these will prevent operation unless the control is or just light up the same indicator used for X-ray tube
switched 'off' then 'on' again. I n such a case, consid- overload. However, inside the control there are often
erable caution is required, and any warning signals or many indicator LED indicators provided to indicate
codes should be investigated first. sequence operation or fault indication.Table EL7 indi-


While recent systems may display a fault code, or cates some of the safety interlocks and fault detection
message, older controls may indicate a fault symbol, requirements that may exist.


Table E-7. Typical safety interlocks and fault detection requirements


On power up and Interloclc test for operation of X-ray tube high-tension selection switch and stator
system check. connection relays.


Has X-ray tube housing over temperature switch operated?
On inverter systems, have the banlc of inverter power supply capacitors charged up to
the correct voltage?


Before preparation Has a valid technique been selected?
is permitted. Are the exposure factors within the safe operating area of both the X-ray tube and


the generator?
Entrance door safety switch not activated.


During preparation. I s the current through the X-ray tube filament transformer above a minimum level?
(If below, can indicate open filament connection).
I s the filament current inside the maximum limit?
I s the current flowing in both the 'start'and 'run' stator windings of the X-ray tube
the correct value?
Loolc for illegal voltage on generator transformer primary winding. (In case of an SCR
contactor fault in conventional systems).
Energize a warning light. 'Do not enter'.


At end of Interlock for preparation timers. (Older systems may depend only on the stator
preparation. control; later systems include a timer for minimum filament heating time.)
On exposure request Hand switch exposure request is sent to the required Bucky.
with peripheral The Bucky must move the grid and trigger an interlock to indicate the Buclq is ready
equipment, eg Buclq. for an exposure.This interlock relays the exposure request baclc to the X-ray control.
To commence actual On conventional systems, the expose signal places the timer into operation.The timer
exposure. waits for a synchronization pulse derived from the mains supply voltage, and a t the


correct phase interval operates the SCR contactor.
With a mechanical contactor, the time for the contactor to operate requires a
compensation adjustment.
With an inverter system, the signal to the timer and the inverter may occur a t the
same time. Mains voltage synchronization is not required.


During exposure. The mA is measured. I f mA is higher than a preset detection limit, stop the exposure.
With high-frequency systems, i f kV is excessive, or, after a short measurement time
too low, stop the exposure. Some inverter systems measure the transformer primary
current, and i f too high stop the exposure.


At the end of a A time-up signal may be sent to peripheral equipment.
radiographic I f in high-speed mode, the X-ray tube starter will now produce a brake cycle.
exposure. A filament cool-down timer will operate, so a fluoroscopic exposure cannot be made


until this timer has finished.


Safety and Fault Detection in X-Ray Systems


McClelland, I. R. “Appendix E: X-Ray Equipment Operation.” From the Publication: X-Ray


Equipment Maintenance and Repairs Workbook for Radiographers & Radiological


Technologists, (WHO: 2004).


54




*4.*Troubleshooting*and*Repair*of*XCRay*Systems****Featured*in*this*Section:*****WHO.&“X"Ray&Diagnostic&Equipment.”&Maintenance&and&Repair&of&Laboratory,&Diagnostic&Imaging,&and&Hospital&Equipment&(WHO:&1996),&p.&121"134.&*Strengthening&Specialised&Clinical&Services&in&the&Pacific.&User(Care(of(Medical(Equipment:(A(first(line(maintenance(guide(for(end(users.&(2015).& *&&&&&&&&&&&** *****
55




User Care of Medical Equipment – First line maintenance for end users


73


Troubleshooting – X-Ray Machines


Fault Possible Cause Solution


1.



X-Ray unit does not switch on.



Mains power not connected



Check the machine is plugged
into the mains socket and that all
switches are on.
Replace fuse with correct voltage
and current if blown.
Check mains power is present at
socket using equipment known to
be working. Contact electrician
for rewiring if power not present.



2.



X-Ray machine not exposing,
even when power is on.



Safety interlock is on

Exposure switch cable problem

Internal error



Check safety locks, all switches

Check for any loose connection

Refer to biomedical technician



3.



Poor X-Ray image quality



X-Ray tube problem



Check X-ray film cassette is
correct type and is undamaged

Refer to biomedical technician /
medical physicist



4.



The table does not move.



Table motor or cable problem.

Safety switch or fuse problem

Control circuit problem



Check all cable connections

Check relevant fuse or switch

Refer to biomedical technician



5.



Electrical shocks



Wiring fault



Refer to biomedical technician
immediately


Strengthening Specialised Clinical Services in the Pacific. User Care of Medical Equipment: A first line maintenance guide for end users.


(2015).


X-Ray Troubleshooting Table


56




PART III. FAULT DIAGNOSIS AND REPAIR MODULES
75


Fig 6–1. Unable to obtain preparation, part one


Are there any
warning


indications?
Is this fault code


or a message?


Look in the operation manual
for the meaning of the


message code. If necessary,
contact the service


department.


Proceed to part three.
See text for other possible


areas to be checked.


Has the warning
light turned off?


Can preparation
be obtained now?


Has a suitable
technique been


selected?


Select a correct
technique


End


Proceed to part two for further
tests.


Is a suitable tube
or focal spot


selected?


Select a suitable
tube or focal spot.


On attempting to obtain
preparation, nothing at all


happens


End


End


Yes


No


Yes


Yes


Yes


Yes


No


No


No


No


No


YesIs there a 'door
open' safety
interlock?


End


No


No


Yes


Yes


Check the door-open safety
switch. Make sure it is operating
properly when the door is closed.
See the text for a test procedure.


Can preparation
now be obtained?


Check setting of exposure factors
for possible X-ray tube overload
protection. Include check of focal
spot selection, and minimum KV


X-Ray Troubleshooting and Repair Flowcharts


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


57




X-RAY EQUIPMENT MAINTENANCE AND REPAIRS WORKBOOK
76


E


Fig 6–2. Unable to obtain preparation, part two


On attempting to obtain
preparation, nothing appears to
happen. Th ere are no message


codes or warning lights.


End


On pressing the
prep' button, can
you hear a relay


operate?


Power off. Disconnect the
handswitch cable from the control


desk. With a meter, test for
brocken wires or a faulty switch.


Preparation IS being attempted.
Proceed to part four.
Refer also to the text.


No


Yes


Power off. Turn isolation switch
off. Remove control cabinet


cover, and check for a possible
blown fuse. Refer to module 9
first for precautions in testing


or replacing a fuse.


Is there a faulty
fuse, or tripped
circuit breaker?


Refer to module
9.0 to replace a


fuse.
Contact service


before attempting
replacement.


Proceed to part five.
(See text for other possible


areas to be checked)


Yes


Yes


No


No


No


Yes


Listen at the
X-ray tube. Is


there any sound
on prep'?


Is there a broken
wire or faulty


switch?


Repair the broken wire in the
handswitch cable, or replace the


faulty preparation switch.


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


58




PART III. FAULT DIAGNOSIS AND REPAIR MODULES
77


Fig 6–3. Unable to obtain preparation, part three


On attempting to obtain
preparation, nothing appears to
happen. There is a permanent


message code or warning light.
The procedure in part one has


been carried out. Operation error is
not the cause of the problem.


No


Yes


Yes


Di d the warning
fault light operate


immediatly on
power up?


Th is may be a serious fault.
Contact service for advice before


proceeding. Provide details of
tests carried out.


Di d the
warning light


operate immediatly
after or during the


last exposure?


No


Yes


Contact service. Give full details
of the problem, and conditions


when the warning light operates.


Proceed to 'No exposure part 7'
Reduce kV to 60kV before


attempting another test
exposure.


No


Di d the warning
fault light operate
when attempting


preparation?


Yes


No


Th is may be a serious fault.
Contact service for advice before


proceeding. Provide details of
tests carried out.


See the text for possible causes


See the text for possible causes


Can preparation
now be


obtained?


There may have been a high
tension fault, or excessive mA.


Switch power OFF then ON
again. Test if preparation can


now be obtained


There may be a blown fuse or
tripped circuit breaker.
Contact service before


proceeding.


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


59




X-RAY EQUIPMENT MAINTENANCE AND REPAIRS WORKBOOK
78


E


Fig 6–4. Unable to obtain preparation, part four


On attempting to obtain
preparation, nothing appears to
happen. There are no warning


lights or message codes. However
some sound was observed at the


X-ray tube. This indicates the prep
handswitch is functioning.


No


Yes




Listen carefully at the X-ray tube
during preparation.


Contact service
before proceeding.


Tr y a test exposure with selection
of a different focal spot. (eg, if on


broad focus, try fine focus).


Was a br oken
wire or bad
connection


found?


Contact service
before proceeding.


End


U ndo the ring nut holding the
cathode cable in place. Withdraw


the cathode cable a few
millimeters only and re-insert.


NOTE, do not attempt if this is a
CD mobile.


The cathode cable end has a bad
pin connection. See module 11.3,


High tension cable.


Can preparation
now be obtained?


Contact service
before proceeding.


Can preparation
now be obtained?


Th ere is a strong possibility that
the other focal spot is faulty. Do
not use that focal spot. Contact


service and ask for advice.


As the HT cable end has been
disturbed, refer module 11.3,


High tension cable, before
continuing to use the generator.


End


Yes


No


Yes


Yes


No


No


No


Yes


Are there any
signs of an oil


leak?


Does the X-ray
tube anode appear
to rotate normally?


Switch off. Turn the isolation
power switch off. Locate the stator
connection cable to the tube stand.
Check carefully for signs of a bad
connection or broken wire in the


cable to the X-ray tube.


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


60




Part 5. Other tests
Re f er first to the flow chart, Fig 6–5 page 79, ‘Unable
to obtain preparation, part five’.


T here remain two possibilities to be checked.
● T he wiring to the X-ray tube stator or the housing


ov er-temperature switch is broken or has a bad
connection. This could occur where it enters the X-
ra y tube, or where the cable has received a lot of
flexing or twisting. See module 7.1 page 104.


● T here may be an internal fault or problem in the
generator, but the warning light is also faulty or
b urnt out. Test the light by setting ver y high expo-
sure factors, which would normally cause a tube
ov erload condition. If no warning light illuminates,
then the globe or control circuit is faulty.


● Include the results of all tests, when requesting help
from the service department.


Section 2: No radiograph exposure
T his section assumes you are able to obtain prepara-
tion, the control has indicated preparation is com-
pleted, and is ready for an exposure. On attempting
to obtain an exposure, nothing happens. Or else, the
control appears to expose, but the film is blank or ver y
light. Each part has an associated flow chart. Refer to
these flow charts before reading the text.


Part 6. Operation tests
Refer first to the flow chart, Fig 6–6 page 83, ‘No expo-
sure, part six’.


T he control has indicated it is ready for an exposure.
On attempting to obtain an exposure, nothing appears
to happen. There is no sound from the Bucky. The expo-
sure light does not operate.


PART III. FAULT DIAGNOSIS AND REPAIR MODULES
79


Fig 6–5. Unable to obtain preparation, part five




No


YesWas a wiring break or bad
connection


found?


Check carefully all wiring to the
X-ray tube. Especially check for
a break in the stator cable, or to


the over-temperature safety
switch.


End


Can preparation
now be obtained?


Yes


No


Repair the break in wiring or
loose connection. If a faulty
temperature switch, make a
temporary bypass for testing


purposes.


Was there a
faulty


over-temperature
switch?


Yes


No


It is possible there is faulty or
burnt out warning light. Test by
selecting a very large mA, kV
and time setting. See if the
overload light does illuminate.
Advise the service department of
the results of this test, in addition
to all other tests and
observations.


On attempting to obtain
preparation, nothing appears to
happen. There are no warning


lights or message codes. No sound
was observed at the X-ray tube.


The hand switch and cable tests ok
There are no open circuit fuses or


circuit breakers.


Contact the service department
for advice, and to obtain a new


over-temperature switch or
sensor.


Continue to operate the system
with caution. Monitor the X-ray
tube housing, and stop using if


hot to touch.


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


61




PART III. FAULT DIAGNOSIS AND REPAIR MODULES
85


Fig 6–8. No exposure, part eight


On attempting to obtain an
exposure, the film is blank,


or very under exposed.
Th e exposure indicator operated.
Th e control indicated preparation


was completed, and
ready for an exposure.


Yes


Do the cable
ends appear


OK?
Re fer to module 1 1. 3
High tension cables.


No


Tr y the ageing procedure
described in module 5.1


for the X-ray tube.


Is the test
exposure OK?


Are the test
exposures OK?


Th e X-ray tube may have failed.
Th ere may be arcing in the HT


cable receptacles. See the text for
other possibilities. Call the


service dept for advice.


End


No


Yes


No


Yes


In this situation, a light indicates
a fault. If a microprocessor


controlled system, there may be a
message or error code.


Select low kV (60kV or less)
and a low mA station.
Try a test exposure.


Observe the cable ends for
possible smoke or arcing noise.


This may indicate a high tension
fault, an unstable X-ray tube,


or excessive mA.
Before proceeding, check for a
burning smell at the X-ray tube


HT cable ends.


WHO. “X-Ray Diagnostic Equipment.” Maintenance and Repair of Laboratory, Diagnostic Imaging, and


Hospital Equipment (WHO: 1996), p. 121-134.


62




5.*Resources*for*More*Information*about*XCRay*Systems****Featured*in*this*Section:*****&WHO.&“Routine&Maintenance&Models.”&From&the&publication:&Maintenance(and(Repair(of(Laboratory,(Diagnostic(Imaging,(and(Hospital&Equipment((WHO:&1996).&&&&WHO.&“Fault&Diagnosis&and&Repair&Modules.”&From&the&publication:&Maintenance(and(Repair(of(Laboratory,(Diagnostic(Imaging,(and(Hospital&Equipment((WHO:&1996).&&&&& &**&&&&* *&&&&&
63




*Resources*for*More*Information:&*&**Internal*Resources*at*library.ewh.org:*For*more*information*about*maintenance*and*repair*of*xCray*systems,*please*see*these*resources*in*the*BMET*Library!*& 1. WHO.&“Routine&Maintenance&Models.”&From&the&publication:&Maintenance(and(Repair(of(Laboratory,(Diagnostic(Imaging,(and(Hospital&Equipment((WHO:&1996).&& 2. WHO.&“Fault&Diagnosis&and&Repair&Modules.”&From&the&publication:&Maintenance(and(Repair(of(Laboratory,(Diagnostic(Imaging,(and(Hospital&Equipment((WHO:&1996).&&& *&


64




XCRay*Bibliography:&&&&Engineering&World&Health.&“Preventative&Maintenance&Schedule&for&X"Ray&Viewer.&EWH.&2012.(&& Dilmen,&N.&“Medical&X"Ray&Imaging&ALPo2.”&Wikimedia(Commons,&November&12,&2011.&Retrieved&from:&https://commons.wikimedia.org/wiki/File:Medical_X"Ray_imaging_ALP02_nevit.jpg&&& McClelland,&I.&R.&“Appendix&E:&X"Ray&Equipment&Operation.”&From&the&Publication:&XARay(Equipment(Maintenance(and(Repairs(Workbook(for(Radiographers(&(Radiological(Technologists,&(WHO:&2004).&&&& Strengthening&Specialised&Clinical&Services&in&the&Pacific.&User(Care(of(Medical(Equipment:(A(first(line(maintenance(guide(for(end(users.&(2015).&&&WHO.&“Radiographic,&Fluoroscopic&System.”&From&the&publication:&Core(Medical(Equipment.&Geneva,&Switzerland,&2011.&&&WHO.&“Stationary&Basic&Diagnostic&X"Ray&System,&Digital.”&From&the&publication:&“WHO&Technical&Specifications&for&61&Medical&Devices.&WHO.&Retrieved&from:&http://www.who.int/medical_devices/management_use/mde_tech_spec/en/&&&WHO.&“Stationary&Basic&Diagnostic&X"Ray&System,&Analogue.”&From&the&publication:&“WHO&Technical&Specifications&for&61&Medical&Devices.&WHO.&Retrieved&from:&http://www.who.int/medical_devices/management_use/mde_tech_spec/en/&&&WHO.&“X"Ray&Diagnostic&Equipment.”&Maintenance(and(Repair(of(Laboratory,(Diagnostic(Imaging,(and(Hospital&Equipment((WHO:&1996),&p.&121"134.&&&Wikipedia.&“&X"Ray.”&Wikipedia,&pp.&1"17.&Retrieved&from:&https://en.wikipedia.org/wiki/X"ray&&&Wikipedia.&Basic(Physics(of(Digital(Radiography/The(Image(Receptor.&&Wikibooks.&Downloaded&6/25/2014.&Retrieved&from:&https://en.wikibooks.org/wiki/Basic_Physics of Digital_Radiography/The_Image_Receptor&&&
65




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