Film Processing Q & A Robert L. Metzger, Ph.D.

RAPHEX 2001 Diagnostic Question D9 The imaging System which is best for visualizing small high contrast objects is: A. Computed tomography B. Film-screen radiography C. Image intensified fluoroscopy D. Magnetic resonance imaging E. Ultrasound

RAPHEX 2001 Diagnostic Answer D9 B. Film-screen radiography An example is microcalcifications on mammography

RAPHEX 2002 Diagnostic Question D21 Failure to use adequate fixer for radiographic film processing will: A. Decrease the film contrast gradient B. Decrease film speed C. Increase quantum mottle D. Increase silver reclamation E. Decrease archival storage

RAPHEX 2001 Diagnostic Answer D21 E. Decrease archival storage Fixer removes the undeveloped silver grains from the film base. Failure to remove all the silver grains will result in darkening the film with time. Improperly fixed films will have a brown appearance after a number of years. Silver reclamation will decrease, but the fixer has no effect on film contrast, speed or quantum motile.

RAPHEX 2002 Diagnostic Question D22 Low specific gravity of the developer solution (dilution of the chemistry) for film processing will: A. Increase film contrast gradient B. Increase “base + fog” C. Decrease film speed D. Decrease archival storage E. All of the above

RAPHEX 2002 Diagnostic Answer D22 C. Decrease film speed Lowering the specific gravity of the developer is similar to diluting the chemistry with water, and results in a lower film speed and lower film average contrast gradient. The developer has no effect on archival storage. Dilution of the chemistry will also decrease “base + fog” to its lowest level.

RAPHEX 2002 Diagnostic Question D23 Consider the three characteristic curves in the diagram. Which statement is false?

D23 Answer Choices A. System B has the highest contrast B. System C has the widest latitude C. System A has the highest maximum density D. System B has the highest base- fog density E. System C is the fastest

RAPHEX 2002 Diagnostic Answer D23 E. System C is the fastest System A is the fastest, I.e., requires the lower exposure to give a net density (density minus base + fog) of 1.0

RAPHEX 2003 Diagnostic Question D25 A radiograph with an optical density (OD) of 3.0: A. Transmits 1/3 times as much light as a film with an OD of 1.0 B. Has a combined OD of 6.0 when placed over another film of OD 2.0 C. Looks “light gray” on a standard view box D.Transmits 0.1% of the light incident upon it

RAPHEX 2003 Diagnostic Answer D25 D. Transmits 0.1 % of the light incident upon it Optical densities are additive, so the net OD of both films is 5.0. An OD of 3.0 looks black on a standard view box. OD=log10(I/T), where I and T are the incident and transmitted light intensities. For OD=3.0, T=0.001, and for OD=1.0, T=0.1

RAPHEX 2003 Diagnostic Question D29 The following film processor parameters all affect mammography image quality except: A. Nitrate depletion B. Developer concentration C. Developer temperature D. Replenishment rates E. Developer immersion time

RAPHEX 2003 Diagnostic Answer D29 A. Nitrate depletion B-E directly influence the density and speed of the various film/screen systems. Although bromine concentration in the developer affect both speed and contrast, nitrate depletion has no effect on the development of mammography films.