Diagnosis of renal pelvis subepithelial hemorrhage using unenhanced helical CT.

1023 41-year-old man developed right flank pain and gross hematuria over a 48-hr period. He was taking warfarin (Coumadin; DuPont, Wilmington, DE) because of a prosthetic aortic valve and previous coarctation repair; after a recent dose change, his international normalized ratio (INR) was markedly elevated at 10.0 (therapeutic range, 3.0–4.5). Results of previous investigations for self-limited episodes of hematuria had been negative. Unenhanced helical CT of the urinary tract showed high-attenuation thickening of the right renal pelvis and proximal ureter, indicative of subepithelial hemorrhage (Fig. 1A). Contrast-enhanced CT (Fig. 1B) showed a delay in contrast excretion, mild calicectasis, and constriction of the renal pelvis. No parenchymal lesions were revealed. CT urography performed 1 month earlier (Fig. 1C) had shown a healthy right kidney and ureter. Hematuria and pain resolved after correction of coagulopathy. Discussion The incidence of hemorrhage in anticoagulated patients varies from 4% to 24% [1]. Hemorrhage occurs most commonly from the urinary tract (in as many as 40% of patients) [1]. Anticoagulation may unmask preexisting abnormalities such as calculi, parenchymal and epithelial neoplasms, nephritis, cystitis, or benign prostatic hypertrophy. Bleeding may be parenchymal, subcapsular, perinephric, or, rarely, subepithelial, as in this patient. Diagnosis of Renal Pelvis Subepithelial Hemorrhage Using Unenhanced Helical CT Alexi Phinney 1,2 , Julian Hanson 1 , Lee B. Talner 1