Comparison of Conventional and Triple Bolus Computed Tomography Urography Protocols for Radiation Dose Reduction in Hematuria Evaluation: A Randomized Controlled Trial.

Abstract

PURPOSE\nComputed tomography urography is the diagnostic tool of choice for evaluating hematuria. In keeping with the ALARA (as low as reasonably achievable) principle, we evaluated a triple bolus computed tomography (TBCT) protocol designed to reduce radiation exposure.\n\n\nMATERIALS AND METHODS\nPatients with macroscopic or microscopic hematuria were prospectively randomized to conventional CT (CCT) (n=100) or TBCT (n=100). The TBCT protocol entails two scans: pre-contrast scan followed by three contrast injections at 40 seconds, 60 seconds, and 20 minutes prior to the second scan to capture all three phases. The CCT protocol requires four scans: pre-contrast scan, and three post-contrast scans at the corticomedullary, nephrographic, and excretory phases. Radiation exposure and the detection of urologic pathology were recorded based on radiology reports.\n\n\nRESULTS\nThere were no differences in patient demographics or BMI between the two groups. TBCT exposed patients to 33% less radiation (1715 vs. 1145 mGy*cm, p <0.001 for CCT and TBCT, respectively). For macroscopic hematuria, the pathology detection rates were 70% for TBCT and 73% for CCT (p=0.72). For microscopic hematuria, the detection rates were 59% for TBCT and 50% for CCT (p=0.68). In both groups, the rates of detection of urolithiasis, renal cysts, urological masses, bladder pathology, and prostate pathology were no different between TBCT and CCT.\n\n\nCONCLUSIONS\nIn both the setting of macroscopic and microscopic hematuria evaluation, triple bolus CT significantly reduces radiation exposure while providing equivalent detection of genitourinary pathology compared to conventional CT. The ability to detect upper tract filling defects was not specifically tested.