Evaluation of Technologist-Controlled Factors Used During CT Kidney Stone Examinations

To identify technologist-controlled factors to decrease dose and improve image quality and evaluate their use during computed tomography (CT) kidney stone examinations.

Online scholarly databases were searched to acquire peer-reviewed, published articles involving methods of optimizing radiation dose during CT. These articles were reviewed, and the technologist-controlled factors identified were protocol selection, patient centering in the bore, and scan length. The author retrospectively reviewed CT kidney stone examinations performed at a free-standing emergency department to evaluate the use of these factors.

Technologists consistently chose the correct scan protocol. Reviewed literature was used to determine the acceptable variance for positioning at isocenter and overscanning beyond anatomical landmarks. All patient positioning was off-center in the vertical direction, and in 3 of those examinations, patient positioning was off-center more than the 3 cm threshold. Horizontal off-center positioning was less frequent. All examinations had some amount of overscan, with 73.1% of patients being overscanned more than the determined threshold of 10% of total scan length.

Accurate labeling of protocols at the console assist technologists in choosing protocols correctly. Technologists were inconsistent with patient centering and scan range. The amount of which images were off-center was consistent with previous research studies, while the amount of overscan was less than that found in previous studies.

Technologists have an important role in optimizing patient radiation dose. Education and quality assurance could help technologists gain awareness of these factors and use them effectively.