Nonobstructive right circumcaval ureter associated with double inferior vena cava.

Computerized tomography (CT), intravenous pyelography (IVP), and ultrasound characteristics of nonobstructive right circumcaval ureter associated with double inferior vena cava in an adult is presented. The CT appearance of the retrocaval segment of the circumcaval ureter which was detected as a "thin, long line" suggests it might be a useful sign in the incidental diagnosis of the anomaly even on noncontrast-enhanced abdominal CT examination. Because of the unique IVP appearance of circumcaval ureter in this case, a new classification is presented.