Antegrade MDCT pyelography for the evaluation of patients with obstructed urinary tract.

Objective: The purpose of this study was to design an alternative imaging technique to CT urography in patients with high-grade urinary tract obstruction, with or without impaired renal function, that uses the superior resolution of MDCT and avoids IV contrast material administration.

Conclusion: Antegrade MDCT pyelography is an alternative imaging technique to CT urography in patients with high-grade urinary tract obstruction with or without impaired renal function. It enables accurate diagnosis of the level of obstruction, as well as its etiology, including nephroureterolithiasis, urothelial tumors, primary congenital megaureter, uretero-pelvic junction stenosis, ureteral edema, ureteral stricture, retroperitoneal fibrosis, and pelvic lymphadenopathy.