A satisfactory lateral lumbar spine radiograph is taken using 200 mA,0.6 sec,94 kVp,and 40 inches SID. If an increase in SID to 60 inches is desired,which of the following technique changes will produce a radiographic density most similar to the original?

Question

Quizplus · Accepted Answer

When the SID is increased from 40 to 60 inches, the radiation intensity reaching the image receptor decreases by a factor of 2.25 (60/40)^2. To compensate for this decrease, the exposure time needs to be increased by the same factor, 2.25. Therefore, the correct option is B, which has an exposure time of 1.33 seconds, which is 2.25 times the original exposure time of 0.6 seconds. The other options do not have the appropriate combination of mA, exposure time, and kVp to maintain the same radiographic density when the SID is increased.

A Satisfactory Lateral Lumbar Spine Radiograph Is Taken Using 200