Minimizing radiation exposure in pediatric nephrolithiasis: The effectiveness of a low-dose computed tomography protocol

PURPOSE: Ultrasonography is the recommended first-line investigation for the diagnosis of pediatric nephrolithiasis. Despite higher sensitivity and specificity for this condition, computed tomography is reserved for more complex cases due to its radiation exposure. Despite increasing stone prevalence in the pediatric population, there is a lack of low-dose computed tomography pediatric urolithiasis protocols and descriptions of low-dose protocols are sparse. Herein we report the development and implementation of a low-dose protocol to reduce radiation exposure to this vulnerable population. MATERIALS AND METHODS: A novel low-dose computed tomography protocol was designed through multidisciplinary collaboration, literature review, and phantom trials. Patients undergoing computed tomography for urolithiasis assessment were evaluated using the novel low-dose protocol and were compared to a retrospective cohort. Radiation reduction was characterized using descriptive statistics and comparative analysis. RESULTS: Mean (± standard deviation) age for the low-dose group was 12.6 ± 4.2 years (n = 26) compared to 12.4 ± 3.7 years for the standard-dose group (n = 15). The low-dose protocol reduced radiation dose when compared to the standard-dose group by 55.5 % (≥45 kg) (p = 0.02) and 27.8 % (<45 kg) (p = 0.03). The low-dose protocol visualized stones seen on ultrasound with 100 % accuracy (n = 6), and in 61.5 % (n = 16/26) of patients. There was no difference in stone sizes between groups. CONCLUSIONS: Reduced-dose computed tomography protocols are effective for assessing urolithiasis while reducing radiation exposure. Implementation of reduced-dose computed tomography protocols in cases of suspected urolithiasis is advised to limit radiation exposure while maintaining diagnostic imaging detail.