IAEAInternational Atomic Energy Agency

RADIATION PROTECTION INDIAGNOSTIC AND

INTERVENTIONAL RADIOLOGY

Part 15.7: Optimization of protection in radiography

Practical exercise - processor

IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology

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Overview / Objectives

• Subject matter : quality control of the processor

• Step by step procedure to be followed to implement the considered QC test:

• film storage, cassette and screen, sensitometry

• Interpretation of results

IAEAInternational Atomic Energy Agency

Part 15.7: Optimization of protection in radiography

Topic 1: Processor evaluation (film storage, cassette and screen, sensitometry)

IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology

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What Minimum Equipment is Needed?

• Thermometer

• Sensitometer

• Densitometer

• Manufacturer’s cleaning solutions

• Ultraviolet (“Black Light”) light

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Film Processor QC

• Most important QC features :• proper film storage

• cassette and screen care

• processor chemical care

• sensitometry

• artifacts

• processor cleanliness

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Film Processor QC

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Film Processor QC - Film Storage

• Film should be stored in cool, dry conditions

< 26° C, 30-60% relative humidity

• Film storage area should be adequately shielded from x-ray exposure

• Too low humidity allows static discharge

• Storage period must not be too long

• Stack film boxes vertically to avoid pressure on films

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Cassette and Screen Care

• Clean screens periodically to avoid dust shadows

• Use manufacturer’s recommended cleaning solutions

• An ultraviolet (“Black Light”) light can show up dust

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Processor Chemical Care

• Chemicals (developer and fixer) degrade with time and use

• Developer in particular will oxidize (go brown) and become depleted with use resulting in poor quality (reduced contrast and film speed) films

• Fixer will change pH and lose emulsion hardener

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Film Processor QC

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Processor Chemical Care

• Chemicals must be replenished (continual automatic replacement)

• Use manufacturer’s recommendations

• Check the developer temperature daily - processing is very sensitive to temperature

Note: If the number of films processed per day is low, it will be necessary to use flood replenishment. See Flood replenishment: a new method of processor control. Frank ED, Gray JE, Wilken DA. Radiol Technol. 52:271-275, 1980

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Sensitometry

• Sensitometer and densitometer required

• Essential to keep the process under control

• To be performed daily

• Main parameters investigated:

• Base-plus-fog

• mid-density

• density difference (See reference to ACR Quality Control Manual, and

Quality Control in Diagnostic Imaging, last slide)

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Film Processor QC - Artifacts

• Anything on the film which is not related to the x-ray image

• Examples :• dust marks, static discharge

• fixer stains (poor washing)

• film storage problems

• processor problems (roller marks, scratches)

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Film Processor QC - Processor Cleanliness

• All processors will eventually get dirty

• Clean processor according to manufacturer’s instructions

• Daily cleaning of entrance trays and cross-over racks is essential

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Where to Get More Information

• Part XIII.8 “Optimization of protection for Mammography” Practical exercise

• Flood replenishment: a new method of processor control. Frank ED, Gray JE, Wilken DA. Radiol Technol. 52:271-275, 1980

• American College of Radiology Mammography Quality Control Manual, Reston VA, 1999.

• Quality Control in Diagnostic Imaging, Gray JE, Winkler NT, Stears J, Frank ED. Available at no cost. http://www.diquad.com/QC%20Book.html