Urological Survey 543 Hematuria Evaluation With MDCT Urography: Is a Contrast-Enhanced Phase Needed When Calculi Are Detected in the Unenhanced Phase? Song JH, Beland MD, Mayo-Smith WW Department of Diagnostic Imaging, Rhode Island Hospital-Warren Alpert Medical School of Brown Univer- sity, 593 Eddy St, Providence, RI 02903 AJR Am J Roentgenol. 2011; 197: W84-9 Objective: The purpose of this study was to assess the added utility of the contrast-enhanced phase of MDCT urography (MDCTU) when urinary tract calculi are detected in the preliminary unenhanced phase. Materials and Methods: A computer search of CT reports with the term “hematuria” yielded the records of 1209 patients who had undergone MDCTU. The reports of 286 MDCTU examinations in which urinary tract calculi were detected were identiied, and two blinded abdominal radiologists reviewed the images to ind a second source of hematuria. The unenhanced images were reviewed irst, and the indings were compared with those on the subsequent contrast-enhanced images. The aggregate indings of the 286 examinations in which calculi were present were compared with those of the 923 examinations in which calculi were absent. The follow-up diagnosis was based on histopathologic indings, indings at urologic procedures, or the imag- ing diagnosis. Results: In 119 of the 1209 patients (10%), 127 lesions other than urinary tract calculi were identiied as pos- sible sources of hematuria. Eighty-two lesions were diagnosed in 77 patients (6%) at follow-up evaluation. A second source of hematuria was found in 19 of the 286 examinations (7%) with calculi compared with 58 of the 923 examinations (6%) without calculi (p = 0.828), and contrast was needed to make a speciic diagnosis in 16 of the 19 examinations (84%). Conclusion: When urinary tract calculi are identiied at MDCTU, the rate of detection of other potential causes of hematuria is not different from that in MDCTU examinations without calculi. The contrast-enhanced por- tion of the MDCTU examination is needed even if calculi are seen because important pathologic changes are diagnosed only after the contrast-enhanced phase. Editorial Comment Multi-detector computed tomography (MDCT) urography has become the “gold standard” imaging technique for the investigation of patients with hematuria. MDCT urography protocol should be designed to optimize visualization of urolithiasis, the renal parenchyma and the urothelium. Although there is no consen- sus how to do it, most of the time, patients are imaged with the three-phase protocol: nonenhanced acquisition through the abdomen and pelvis (for detecting urolithiasis), nephrographic phase (through the abdomen) and delayed excretory phase (through the abdomen and pelvis). Using this protocol in our institution the patient effective radiation dose varies from 20-22 mSv (almost the double of the effective dose from an excretory urography, 10-12 mSv). As pointed out by the authors, the American Urologic Association states that in patients with mi- croscopic hematuria and at low risk of malignancy, no further imaging is needed if unenhanced phase of CT examination reveals urolithiasis. Since in the authors´ experience, second source of hematuria had practically the same frequency in the group of patients with calculi (7%) to those without calculi (6%), they concluded that complete MDCT urography protocol should be performed even in these patients at low risk of malig-