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

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

Methods: 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.

Results: 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.

Discussion: 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.

Conclusion: 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.