Retention of the water-soluble contrast medium in the urinary and genital tracts.

Retention of contrast medium in the renal pelvis for several days after urography is illustrated in 2 cases of obstructing urinary stones. In a third case water-soluble contrast medium was used for retrograde pyelography before nephrectomy and was retained in the stenotic ipsilateral ureter 7 1/2 months after the operation. A further case exemplifies retention in the seminal vesicles 2 months after vasoseminal vesiculography.