UC Irvine

CT imaging predisposes patients to high levels of radiation. In this study, we retrospectively compared the radiation dose of triple-bolus computed tomography (TBCT) and conventional CT (CCT) urography protocols, analyzed the effects of body mass index (BMI) on radiation dose in each group and assessed image quality.

We retrospectively reviewed the images of patients who underwent CCT or TBCT imaging in the management of renal cortical neoplasms. We used standard volumetric CT dose index (CTDIvol) and dose length product (DLP) to estimate radiation exposure. In addition, 2 urologists rated the quality of 20 CT images from each group using a survey with a 5-point Likert scale. The survey consisted of 10 questions relating to the ability of the scan to identify relevant anatomy.

The study included 120 patients. CTDIvol and DLP were 28.7% and 40.4% lower in the TBCT protocol, respectively (both P<.001). Increased BMI was associated with a higher DLP for the CCT group compared with the TBCT group (P<.001). The effect of BMI on CTDIvol did not differ between the CCT and TBCT groups. There was no difference in the urologists’ assessments of CT image quality.

In patients with renal cortical neoplasms, TBCT provides comparable image quality to CCT, with lower ionizing radiation exposure without compromising image quality. Obese patients may benefit more from TBCT scans.