Step by Step of Radiographic
Processing
(A good practice´s manual)
Ana Cecília Pedrosa de Azevedo
Sergio Ricardo de Oliveira
Centro de Estudos da Saúde do Trabalhador e Ecologia Humana — CESTEH
Rio de Janeiro 2005
2
INTRODUCTION
In Brazil, it was published in 1998, the Norm “Portaria 453/98” by
the Minister of Health, establishing the “Directives of Radioprotection in
Medical and Odontological Radiodiagnosis”. Since then, all medical institution
that makes use of ionizing radiation as a diagnostic method, must follow the
requirements contained in that norm.
Besides this, other two laws have been published, one giving
orientations with respect to architectural projects of medical installations (RDC
50/02) and another with respect to the appropriate disposal of chemical
products from radiology departments (RDC 306/04).
One of the main requirements of the Portaria 453/98 is the need
of the implementation of Quality Assurance Programs (QAP) in medical and
odontological radiodiagnosis departments. The QAP have as main objective to
guarantee the production of a high quality image, imparting the lowest possible
dose to the patient and at a reduced cost. The Quality Control (QC) of
processing systems is one of the most important aspects in the implementation
of these Programs.
There are three main steps to generate a radiographic image:
formation of the latent image, film processsing and image visualization. All these
steps are of equal importance since they interfere in the final image quality,
allowing the production of a good radiograph that will contain all the anatomical
details necessary to the elaboration of a correct diagnosis report.
The objective of this manual is to provide basic instructions and
hints about good practices in radiographic processing. The manual includes
considerations about the dark room, the automatic processor and the chemical
products as well as its accessories (cassettes, screens and films). It presents
3
also an orientation on how to implement the sensitometric control of the
automatic processors used in radiology departments.
One of the main requirements for a good processing is that in the
department the processors, films, chemical products and accessories are all
from the same manufacturer, the so-called “crossed system”. This requirement
is essencial for the production of a high quality image. If this requirement is not
obeyed, the image can be degraded and the dose imparted to the patient,
become inadequate.
Another important aspect concerns the cleaning conditions of the
dark room, the processor and its accessories. Lack of cleaning ness and the
presence of dust can cause artifacts in the radiographic image that can hide
important radiological signs, necessary to a correct diagnosis.
4
SUMMARY
1 DARK ROOM...................................................................5
1.1 ENVIRONMENTAL CONDITIONS...............................................................................................................5
1.2 LIGHT TIGHT TEST.........................................................................................................................................7
1.3 SAFE LIGHTS.....................................................................................................................................................8
1.4 FOG TEST............................................................................................................................................................9
1.5 CLEANING.........................................................................................................................................................11
2 AUTOMATIC PROCESSOR................................................... 13
2.1 TRANSPORT SPEED ......................................................................................................................................14
2.2 REPLENISHMENT RATE ..............................................................................................................................14
2.3 CLEANING AND PERIODICAL MAINTENANCE...................................................................................15
3 CHEMICAL PRODUCTS ...................................................... 16
3.1 CHEMICAL PRODUCTS PREPARATION...................................................................................................16
3.2 CHEMICAL EFFLUENTS...............................................................................................................................19
4 ACESSORIES................................................................ 20
4.1 FILMS................................................................................................................................................................20
4.2 SCREENS ..........................................................................................................................................................22
5 ARTIFACTS ................................................................. 24
6 VIEWING BOXES ........................................................... 26
7 SENSITOMETRY ............................................................ 27
8 REFERENCES ................................................................ 32
9 CHECK LIST................................................................. 34
5
1 Dark room
The dark room is the location where the radiographic films are processed.
According to Brazilian legislation the room (RDC 50/04) this room must have
adequate dimensions with respect to the number of processed films and the
quantity of technicians who work in the department. Inside the dark room there
must be only: the automatic processor (or the tanks with chemicals is case of
manual processing), a box to keep the unprocessed (virgin) films, the safe light
and the cassettes.
1.1 Environmental conditions
• The ambient temperature inside the dark room must be kept from 10ºC
to 21ºC.
• The relative humidity must be around 30% to 50%.
• The ventilation should be evaluated by properly trained personnel who
will guarantee that there are, at least, 10 complete changes of air per
hour.
• The exhausting system is of major importance e and should be
designed according to the dark room dimensions. The exhauster should
be preferably directly connected to the processor exit.
• The dark room walls should of light color and recovered with mat
material (preferably) easy to clean and resistant to the chemical
reactions of the chemical products used in the processor as well as to
the cleaning meterials.
• The ceiling must be solid in order to avoid dust falling as well as
humidity from coming from the upper pavement (if applicable).
6
• The use of open shelters in not recommended due to the possibility of
dust accumulation. Instead, it is recommended the use of furniture
with doors, preferably located on the lower side of the working table.
• Safe light(s) must be installed inside the dark room according to the
recommendations of part 1.3 of this manual. The safe light(s) must
provide an appropriate luminance level to allow the staff to work inside
it and at the same time not fogging the films.
• The interior of the ark room must be free of any objects other than
those absolutely necessary to the processing procedures, such as
chemical products, boxes, clothes, radios, etc…
Figure 1 – Interior of a dark room in good conditions
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1.2 Light tight test
The importance of light tighthness is fog reduction. To check light
tightness follow the steps below:
• Turn on all light of rooms adjacent to the dark room;
• Go inside the dark room and turn off all sources of light inside it,
includind the safe light;
• Stay inside the dark room for at least 10 minutes (period of time
necessary to visual accommodation);
• Mark all locations where you can see external light, so that they can be
repaired.
After repairing the eventual light leaks the luminance level must be
checked. This measurement is performed with a photometer (or luximeter) as
seen in figure 1. The measured value must be at maximum 2 lux, with the safe
light turned off and of 10 lux under normal working conditions (safe light turned
on).
Figure 2 – Photometer
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1.3 Safe lights
One or more safe lights are installed inside the dark room to allow a
proper illuminance level so that the operator can see inside it without fogging
the films. The safe light is composed of a metal box, a white bulb and a filter.
The maximum bulb power should be 15 watts. The distance between the safe
light and the manipulation/working surface should be, at least, 120 cm. The
filter is the most important part of the safe light and must be suitable to the
type of radiographic film used in the department. The most common type used
with ortochromatic films (green base) is the red filter. Special attention must
be given when installing the filter since it has a gel on one side and this side
must be installed facing the external part not in the bulb direction. The
installation date must be registered. It is important to check with the
manufacturer the replacement recommendations and the useful life. In general,
for a safe light that is on during 10 hours a day, the filter durability is around 4
months. If the safe light is appropriate, the radiographic films will not fog.
Figure 3 – Safe light and filter
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1.4 Fog test
The fog in the radiographic film can have several origins:
• Ionizing radiation;
• “Safe” lights, that do not follow the above mentioned
recommendations;
• “Unsafe lights”, that can be: light leakage entering the dark room,
generally around the doors, the processor and the film bins, defective
cassettes, luminous dials and perforations in the ceiling, among others.
The fog test checks if there are light leakages that can be fogging the
film. High levels of fog can cause loss of contrast in the radiographic image and
degrade image quality.
The most effective test to evaluate fog level in the dark rooms is to
expose the radiographic film to a sensitometer light. A sensitometer is an
equipment that emits light with the same characteristics of the light coming
from the screens. Therefore, it serves to simulate an exposure to the X rays.
The film exposure must be performed in four steps according to figure 5, in
such a way that the strips be uncovered, one by one, and being exposed to time
of 4, 2, 1 and 0 minutes after exposure respectively. After this procedure,
process the film normally and compare the results of the film darkness (optical
Density) of each strip. The results obtained will be compared with the
“standard” or “reference” film that was obtained before exposing the film to
the sensitometer light, however, with all safe light(s) turned off.
The film darkness is measured using a densitometer (equipment that
evaluates the optical density-OD). The results must show that the difference
between the standard and the real film, obtained at times 0, 1, 2 and 4 minutes,
must be at most 0,05.
10
Figure 4 – Densitometer (L) and sensitometer (R).
Dark rooms that are approved in the 4 minutes test are considered
in excellent conditions, Those approved in the 2 minutes test are still considered
approved, however, if the dark room is approved only in the 1 minute test it must
be checked for light leaks.
For the test, it is recommended that only one film is used,
according to figure 5. A cardboard can be used to cover the part of the film
that must not receive the ambient light.
Figure 5 – Cardboard partially covering the film (L). Radiographic film that has been
uncovered in four steps (R) producing four different fog levels.
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1.5 Cleaning
Cleaning is of major importance since dust and grease may cause
artifacts. Cleaning must be performed daily and include all surfaces: floor, table
top, film bins, and especially the processor entrance tray. A moisturized soft
cloth must be used. Vacuum first, if necessary. Clean the entrance processor
tray at last.
When mammographic films are handled, the cleaning procedures
must be performed twice a day.
Clean regularly the air conditioning filter as well as the exit of the
exhausting air exit (if it is not directly connected to the processor exit).
Use a UV and dark light system to check the presence of dust and
grease in the dark room and in the screens. Dust is enhanced by black light,
while grease in enhanced by UV light. Care must be taken with the eyes, when
handling such a device.
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Figure 6 – Above (L) the entrance tray of the processor with the dark room light turned on. On the right side, the same tray with the dark room light turned off and the black light on. Below
the UV black light system.
13
2 Automatic processor
The basic scheme of an automatic processor is shown in figure 7.
The film to be processed is inserted in the processor tray and automatically
pulled by a mechanic transport system. The film crosses three tanks. The first
with developer, the second with fixer and the last with water. In the last
processing step is passes through the drying section.
Figure 7 – Scheme of an automatic processor
ENTRADA
SAÍDA REVELADOR
FIXADOR
LAVAGEM
SECAGEM
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2.1 Transport speed
Transport speed is defined as the time necessary to a radiographic
film to pass through each section of the processing cycle. (developing, fixing,
washing and drying). The dry-to-dry time is the total time that the film takes to
be completely processed.
These times are measured with a chronometer and shouldn´t vary
more than 3% with respect to manufactures´recommendation. In conventional
radiology, the dry-to-dry processing time is 90 seconds and in mammography
(extended cycle) it ranges from 120-150 seconds.
2.2 Replenishment rate
Replenishmnent rate is defined as the amount of developer and
fixer that are introduced in the processor tanks when a film is inserted in the
processor tray. It must be completely defined in terms of film length, number
of films and area of the film to be processed. The system consists of a timer
that is coupled to the processor and is periodically activated. Ex.: during 20
seconds at each 5 minutes, introducing 65 ml of developer in the tank.
When the processor develops a reduced number of films per day,
flooded replenishment is recommended to keep the activity of the chemical
products. The automatic processor has also a system of re-circulation pumps to
keep the chemicals homogeneous and at Constant temperature.
The replenishment rate ranges from 60 to 600ml/min for the
developer and from 80 to 800ml/h for the fixer. Attention to the difference in
units: for the developer it is per minute whilst for the fixer it is per hour.
Therefore it is clear that the quantity of developer is much bigger than the
fixer.
15
2.3 Cleaning and periodical maintenance
One of the main factors that affect the processing performance is
to keep an excellent cleaning standard and periodical maintenance. The cross
over rolls must be cleaned daily. The upper cover must be kept open overnight to
avoid water condensation and consequently the dilution of the chemicals.
Figure 8 – Cleaning the cross over rolls (L), keeping the upper cover open overnight (R).
Some situations contribute to cause problems in film processing.
They are:
• Reduced number of films to be processed (< 30/day)
• Films of different manufacturers/types
• Chemical products from different manufacturers.
• Films are not processed every day.
• Inconstant number of films processed per day.
The problems are generally caused in this order: developer, fixer,
drying, cross over rolls, cross over system, film transport system, chemical
products replenishment system and re-circulation system.
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3 Chemical products
The main chemical products used in radiographic processing are the
developer and the fixer. Both are a mix of chemical elements that can be toxic,
carcinogenic and irritating. Therefore, during its preparation it is necessary the
use of appropriate Individual Protective Clothes, such as: gloves, aprons, glasses
and masks. It is important to stress that no chemical products should be kept
inside the dark room.
Figure 9 – Individual Protective Clothes – apron (L), glasses (C) e gloves (R).
The correct preparation of the chemical products, the processors
maintenance as well as the film keeping, must be performed according to the
manufacturer’s recommendations. However, the most usual procedures are:
3.1 Chemical products preparation
The developer and the fixer can be stored for up to two years (if
not prepared), if the ambient temperature is maintained around 21ºC. In the
case of prepared (diluted) products and temperature from 5-30ºC, they can be
17
kept for up to fifteen days, when no floating lid is used and up to six weeks if a
floating lid is used. The use of the floating lid reduces evaporation and avoids
contact of the developer with air reducing its oxidation and increasing its useful
life.
Figure 10 – Floating lid
Another very important component of the processing system is the
water used in the dilution of the chemical products and to wash the films. The
water must be filtered and the filter must be replaced periodically (generally
each 3 months). A 50 µm filter is the most appropriate. The water flux must be
kept from 0.95 to 5.7 l/min.
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Figure 11 – Water filtering system
The water temperature must be from 4.5°C to 29.5°C or up to the
same temperature of the developer. Extreme temperatures can cause problems
in the fixing and washing besides being the cause of artifacts.
The ideal developer temperature depends on the kind of film, the
processing cycle as well as on the manufacturer´s recommendations. Generally,
it ranges from 33.5 to 38.3ºC. The temperature influences directly in the film
speed, in the patient exposure and in the radiographic contrast. Consequently, it
is of major importance that to adhere to manufacturer´s recommendations
keeping the developer temperature within the recommended limits of ±0.3°C.
The developer temperature must be checked daily with a
thermometer placed always in the same location of the tank. Avoid to use
mercury thermometers, prefer to use digital. The water used in the dilution of
the developer must be filtered using a 75 µm filter.
Concerning the fixer temperature it is not so crucial and can range
from 29.4°C to 35°C. There is no need to filter the water used for its
preparation. On the other hand, the drying temperature must never exceed the
manufacturer´s recommendations (generally from 37.8 and 71.2oC), otherwise
artifacts can appear.
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3.2 Chemical effluents
The chemical effluents (developer and fixer) are substances that
can cause harm to human beings as well as to the natural environment. The
developer, after a neutralization process to maintain its pH between 7 and 9, can
be discarded in sewer system.
The fixer, can undergo a silver recovery process and be afterwards
taken to an appropriate treatment station.
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4 Acessories
4.1 Films
The basic structure of a radiographic film can be seen in figures 12
and 13 below. The radiographic film is composed of a base that serves to give
support to the emulsion that will be sensitized and a protective layer. It is
important to stress that the mammographic film has single emulsion while the
radiographic film has double emulsion. The mammographic film presents a mark
in its border to assign the side that contains the emulsion.
Figure 12 – Scheme of a mammographic film
The base must have good stability, adequate water absorption and
be sufficiently transparent. The blue color is used to reduce the radiologist eye
fatigue. The latent radiographic image will be formed in the emulsion and
through the process of development the final image will be formed.
180 µm
10 µm
1 µm Prot. layer
Emulsion
Base
21
Figure 13 – Scheme of conventional radiology film.
The unexposed films must be kept in a place with temperature
between 10 and 21ºC, relative humidity between 30 and 50%, and far from
chemical vapors and heat. It is also necessary that the films be kept in the
vertical position using first the oldest ones.
After processing, the films must be kept at temperatures around
21ºC and relative humidity between 40 and 60%. If these recommendations are
not observed artifacts and film cracking may occur.
To check the efficiency of the washing process, it is recommended
that the fixer retention test be performed. This procedure must be done each
six months, according the procedure described in the following.
Ø Fixer retention test
The fixer retention test is employed to check the amount of
ammonia tiosulfate (hypo) that remained in the processed film. High quantities
of this compound indicate that the film has not been properly washed and that
after some time will present a yellowish appearance in the radiographs. This will
impair image quality. The maximum acceptable hypo limit is 0.02g/m2. This test
180 µm
a
250 µm
˜15 µm
˜1 µm Protect. layer
Emulsion
Base
˜1 µm
˜15 µm
22
is particularly important in mammography since the mammograms are kept for
long periods for comparison purposes. The test consists in dropping a small
amount of hypo in the processed film and comparing the obtained color with a
commercially available standard.
4.2 Screens
The modern radiographic screens are made of rare earth chemical
compounds. These compounds have the property of emiting light when excited by
X rays. Therefore, they are used, in diagnostic radiology, with the aim of
intensifying the film blackening allowing a reduction of patient exposure.
The cleaning of the screens is of major importance to increase its
useful life and allowing to obtain higher quality images. To perform the cleaning,
use preferably special chemical products. However, if they are not available, use
a baby shampoo or neutral soap diluted in water. Check with the manufacturer
about the possibility of using 70 % isopropyl alcohol.
Mammographic screens must be cleaned once a week or more
frequently, if necessary, in order to reduce the appearance of artifacts.
Ø Procedures to clean the screens
ü Choose a clean place.
ü Perform the cleaning, preferably, in the end of the day to allow a
complete drying.
ü Avoid re-using the film that was in the cassette, since when returning
it to the box of films, it can introduce dust in it.
ü Moisturize a soft cloth with a small amount of cleaning liquid (or
shampoo) and pass it gently over the screen surface, always in the
same direction.
23
ü Use another cloth to take out completely the cleaning liquid (or
shampoo).
Avoid putting excess pressure over the screen surface, using hard
tissues such as surgical gauze as well as dropping cleaning liquid directly onto the
screen surface. Clean the cassette external surface with another cloth. Use in
the external parts neutral soap and water or 70 % isopropyl alcohol.
After cleaning the screens, place them over the edge and let dry
for at least 6 hours or preferably, overnight. After cleaning and drying, use an
anti-static brush to remove the remaining dust. Do not touch the brush to avoid
the contamination with grease from the hands. Be extremely careful when
handling the screens to avoid damaging the surface.
After finishing the cleaning process, inspect the screen surface
using a UV lamp to make sure that the cleaning was efficient. If not, repeat the
cleaning process.
Figure 14 – Procedure to clean the screen (L) and drying the screen (R).
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5 Artifacts
Artifacts are any unreal images that appear in the processed
radiographic film. They are “defects” in the films. One of the major challenges
in the implementation of QCP, especially in mammography, is the correct
identification and elimination of artifacts. The main causes of artifacts are:
processing, film handling, X ray equipment, patient positioning and especially
dust in the dark room. The artifacts are classified as positive or negative,
according to their color (white or black). Handling artifacts can originate before
or after the exposure and depend on film granulation. Some examples of
artifacts caused by poor maintenance of the automatic processor are shown
below.
Figure 15 – Images with artifacts from the processor
25
Figure 16 – Images with artifacts from dust in the screen .
Figure 17 – Images with artifacts from light leaks
Therefore, he basic recommendation to eliminate artifacts in to
keep an excellent cleaning standard in the dark room as well as in all acessories
and handle the films with maximum care.
26
6 Viewing boxes
The viewing boxes are used by the radiologists to visualize the
radiographs. They are generally mounted in an open metallic box, inside which
are installed fluorescent bulbs. The frontal part of the box is covered with a
translucent plastic material (generally, acrylic) that allows the light emitted by
the bulbs to cross the radiographic film and reach the radiologist´s eyes. For
this process to be effective, the luminance level of the viewing boxes must be at
least 1500 cd/m2, when analyzing conventional films and 3500 cd/m2, when
analyzing mammographic films.
The illuminance level of the clear room (place where the viewing
boxes are) must be kept below 100 lux to avoid dazziling and unwanted reflexes.
Figure 18 – Viewing box
27
7 Sensitometry
One of the main aspects in the implementation of a QAP is to keep
the film processors working under controlled conditions. The most usual method
to control the automatic processors is called sensitometry. It correlates the
film response with the received exposure.
According to data published in the literature, errors due to
incorrect processing can account for up to 13% of the repeat/reject rates. The
sensitometric control will indicate what are the most appropriate actions to be
taken before any loss of quality is observed in the image. However, before
starting the sensitometric control it is necessary to evaluate the operation
conditions of the dark rooms which must have log fog levels and good hygiene
conditions.
The mage quality, the reproducibility of results as well as the doses
imparted to the patients depend on the processing time and the correct
preparation of the chemical products used in the processors as well as their
temperature. Frequently, the exposure (and consequently the dose to the
patient) is increased in order to speed up the processing time. This is a very bad
procedure that unfortunately is still very frequently employed, especially in
odontology.
The sensitometric curve or HD (Hurter & Driffield) curve relates
the degree of blackening (Optical Density-OD) of the film with the exposure
received by it. It evaluates the contrast, the speed (sensibility) and the value of
base + fog. Regions of low OD are in the feet of the curve and represent base +
fog (OD without exposure). High densities are in the “shoulder” of the curve and
represent the maximum film density.
All the densities useful for diagnosis are in the straight portion of
28
the curve that is also called film latitude (all the gray scale). The constrast is
determined by the straight portion of the curve between the points (or steps)
corresponding to 0.25 and 2.0 above base + fog. The speed is the inverse of the
exposure (in Roentgen), needed to produce an OD = 1.0 above base + fog. Fast
films need less exposure to obtain the same OD than slow films. The speed step
is the one that is nearer to the value 1.2 (1.0 + base + fog).
Figure 19 – H&D curve
The sensitometric method consists in exposing the film to a
sensitometer light, obtaining a sensitometric strip of 21 steps and evaluating the
29
exposure parameters (base + fog, speed and contrast). The equipment needed
for this procedure consists of a digital thermometer, a sensitometer, a
densitometer and a box of films to be used only for the QC.
The results will be inserted in a test protocol that will also contain
the values of developer temperature. When there are variations outside the
recommended limits, corrective actions must be taken. The temperature must be
taken every day in the same tank position and in the same time (same hour of
the day). The initial conditions for the implementation of the sensitometric
control is an average of three consecutive days.
Operation procedures:
• Expose the film to the sensitometer light;
• Develop immediately;
• Evaluate the steps base + fog, speed and contrast;
• Take note of all the results in the control chart.
30
MODELO DE ACOMPANHAMENTO DIÁRIO DA PROCESSADORA
Dias
Responsável
CONTRASTE
VELOCIDADE
BASE +
VELAMENTO
+0,15
+0,10
+0,15
+0,10
-0,10
-0,15
-0,10
-0,15
+0,03
31
QUADRO DE PROBLEMAS MAIS PROVÁVEIS DE PROCESSAMENTO
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Arranhado 2 2 3 2 3 2 2 1 1 2 Úmido 3 2 2 2 2 1 2 3 2 4 Aumento Véu de Base 1 5 4 4 4 3 2 2 Com Impurezas 2 2 2 2 2 3 1 3 2 2 2 2 3 Transparência Insuficiente 2 2 2 2 3 1 2 Redução do Contraste 1 1 2 3 1 2 2 4 3 2 2 Aumento do Contraste 1 1 1 Revelando Lentamente 1 2 3 3 2 2 5 Revelando Rapidamente 1 1 2 2 3 5 3 4 4 3
Causas Prováveis
Ocorrências Observadas nos Filmes
32
8 References
Secretaria de Vigilância Sanitária do Ministério da Saúde. Regulamento Técnico:
"Diretrizes de Proteção Radiológica em Radiodiagnóstico Médico e
Odontológico", publicado em 02/06/98, Brasília, Brasil, Portaria # 453/98.
National Council of Radiation Protection and Measurements. Quality Assurance
for Diagnostic Imaging Equipment. Report N° 99. Bethesda: NCRP;1988:44-60.
Papp J. Quality Management in the Imaging Sciences. St. Louis: Mosby, 1998.
Hourdakis CJ, Delakis J, Kamenopoulou V, Balougias H, Papageorgiou E. A pilot
study on the quality control of film processing in medical radiology laboratories
in Greece. Eur J Rad 2000; 33: 24-31.
Medeiros RB, Curci KA, Carrieri FCD. Controle de qualidade no processamento de
imagens radiológicas. Rad Bras 1992; 25: 19-21.
M.Sc. Thesis, L.A.G. Magalhães, Departamento de Radiologia, Faculdade de
Medicina, UFRJ, Dezembro 2001, Rio de Janeiro, Brasil.
Haus AG, Jaskulski SM. Film processing in medical imaging. Madison, Medical
Physics Publishing. 1997.
Gray JE. Light velamento on radiographic films: how to measure it properly.
Radiology 1975;115: 225-7.
Suleiman OH, Showalter CK, Gross RE, Bunge RE. Radiographic film velamento in
the darkroom. Radiology 1984;151: 237-8.
Kimme-Smith C, Rothschild PA, Basset LW, Gold RH, Moler C. Mammogaphic
film-processor temperature, development time, and chemistry: effect on dose,
contrast and noise. AJR 1989;152: 35-40.
Suleiman OH, Slayton RJ, Conway BJ, Reuter FG. Effects of temperature,
chemistry and immersion time on x-ray film. FDA internal publication, USA.
33
Tabar L, Haus AG. Processing of mammographic films: technical and chemical
considerations. Radiology 1989;173: 65-9.
Stears JG, Gray JE, Winkler NT. Evaluation of pH monitoring as a method of
processor control. Rad Tech 1979; 50(6): 657-63.
Frank ED, Gray JE, Wilken DA. Flood replenishment: a new method of processor
control. Rad. Tech. 1980; 52(3): 271-5.
Kofler JM., Gray JE, Sensitometric responses of selected medical radiographic
films. Radiology, 1991;181:879-83.
McKinley B, McCauley A. Spoilt films in X ray departments, BJR 1977; 50: 233-4.
34
9 Check List
Dark room
ü Dimensions adequate to the number of patients.
ü Appropriate floor and walls covering.
ü Crossed system (processor, films, screens and chemical products) all
from the same manufacturer.
ü Absence of alien (strange/foreign) objects to the processing
procedure.
ü Adequate environmental conditions (temperature between 10 and 21oC,
relative humidity between 30 and 50%, sufficient exhaustion).
ü No light leaks.
ü Appropriate number and intensity of safe lights.
ü Fog test performed.
ü Cleaning checked.
Processor
ü Roll speed transport and replenishment rates checked and according to
manufacturers´recommendations.
ü Cleaning of periodical maintenance performed.
ü Use of individual protective clothes/devices during the preparation of
chemical products.
ü Appropriate water filter.
ü Temperature of chemical products checked.
35
ü Chemical wastes correctly disposed.
ü Sensitometric control implemented.
Acessories
ü Films kept correctly (vertical position and environmental conditions
checked).
ü Hypo test performed.
ü Cleaning of screens and cassettes performed.
ü Viewing boxes with sufficient luminance level.
