LESSON 9
CASSETTES/INTENSIFYING SCREENS QUALITY CONTROL TESTS
Section I. FILM-SCREEN COMBINATION QUALITY-CONTROL TEST
9-1.
PURPOSE
Two areas that must not be overlooked when considering the amount of density
on a radiograph are the film-screen combination and the film-screen contact. The film-
screen combination test is to assure that the film-screen combination (image receptors)
used in a department may be used without altering exposure factors (that they are all
the same speed). You, as a radiographer, must always bear in mind the importance of
the film-screen combination and film-screen contact tests. When there is a problem
with different densities on the radiograph, remember that these two quality control tests
help make up the total quality assurance program.
9-2.
EQUIPMENT/MATERIAL
a. Calibrated penetrometer (step wedge).
b. Densitometer.
c. Lead numbers for identification markers.
9-3.
PROCEDURE
a. Use the same exposure room and processor. Avoid as many variations as
possible.
b. Select standard SID--40 inches.
c. Set the control panel:
(1) Select the technique to produce a density of one (1.0) near the middle of
the penetrometer.
(2)
Eighty kVp.
(3)
Two mAs.
d. Select the size of the film holder to be tested.
e. Test all the same size receptors and during the same time period.
MD0062
9-2