JACR: Appropriate use is top strategy to optimize rad dose in abdominal CT
 |
Mahadevappa Mahesh, MS, PhD, of Johns Hopkins University in Baltimore, with colleagues from Harvard Medical School in Boston, reviewed practical strategies for reducing radiation dose associated with abdominal CT exams.
Imaging of the abdomen and pelvis represents the most frequent application of CT, contributing to more than one-third of all CT exams.
The first advice offered by Mahesh et al is to make sure the examination is warranted in the first place.
“The importance of ensuring the appropriateness of CT for a given clinical indication cannot be overemphasized for radiation dose reduction,” wrote the authors. “When not clinically indicated, not performing a CT examination is certainly the best radiation dose reduction strategy.”
After ensuring CT is the best strategy, the authors recommended starting with mapping of clinical indications to provide adequate lesion visualization. While a lower dose CT may not impair image quality for some lesions, such as vascular abnormalities or colonic polyps, it may hinder the ability to see small lesions of the liver and pancreas.
Then the authors advised personalizing protocols based on patient size or weight. This is especially true for abdominal CT in children where scanning parameters must be adapted more aggressively for patients of different sizes.
The use of automatic exposure control is necessary to allow the adaptation of tube current on the basis of patient size, though on older systems without automatic controls, tube current must be adjusted manually.
The authors also advised confining scan range to the region of interest and encouraged users to benchmark their protocols against recommended diagnostic reference values for radiation doses. Discussing procedures thoroughly with patients to make sure voluntary or respiratory movements are minimized can reduce the need for repeat scanning.