f. Select the tomographic technical factors at 60 kVp and approximately
50 mAs.
g. Select the cut level at 15 cm above the table.
h. Make the exposure.
i.
Process the film.
j. Record the technical factors used and the tomographic parameters on the
data form and the radiograph.
k. Repeat the procedure for other cut levels of 5, 10, and 20 cm.
6-4.
EVALUATION AND INTERPRETATION
a. Place the test film on the illuminator.
b. Determine which wire is in the sharpest focus.
c. Use the scale to determine the corresponding cm height.
d. Compare the measure value of the cut level to the indicated value.
e. Record the difference on the data form.
f. Be aware that the cut level accuracy depends on the type of tomographic
equipment being evaluated.
(1) For an add-on linear system, plus or minus five millimeter (mm)
accuracy or better is acceptable.
(2)
For more sophisticated systems, plus or minus one mm accuracy is
acceptable.
(3)
The cut level should be approximately the same for all cm levels.
6-5.
PREVENTIVE MAINTENANCE
Always perform preventive maintenance by retesting after any service repair.
MD0062
6-4