This study was designed to evaluate the diagnostic accuracy of multidetector-row spiral CT (MDCT) for the staging of urothelial carcinoma of the upper urinary tract and to assess the enhancement pattern.

Sixty-seven patients with 76 histologically proven urothelial carcinomas of the upper urinary tract from 2003 to 2008 were included in this study. Imaging was performed with either a 64-channel or 16-channel MDCT scanner in the precontrast, cortical and excretory phases. Two radiologists who were blinded to the pathological results retrospectively reviewed the MDCT examinations in consensus. Tumor location, margin, peripelvic or periureteral spread, decreased renal parenchymal enhancement, dilatation of the upper urinary tract, the presence of lymphadenopathy and of a metastasis were described. Enhancement patterns of tumors were analyzed and were compared according to the WHO grade.

Thirty-eight tumors were identified in pelvocalyceal systems and 35 tumors were indentified in the ureter. The overall staging accuracy was 68.7%. The mean number of Hounsfield units of tumors in the cortical phase (91.4±25.2 HU) was statistically higher than for tumors in the excretory phase (80.5±15.1 HU). No significant differences for attenuation of tumors correlated with WHO grades.

MDCT is an excellent modality for the detection and staging of upper urinary tract urothelial carcinoma. The enhancement pattern can be a helpful finding in the detection of urothelial carcinoma.