Retrograde pyelography (also known as retrograde pyeloureterography) is a method of imaging the upper urinary collecting system. After IVU and CTU were developed, it has been rarely performed as a primary study, but it still has a few potential indications as a secondary study.
- nonvisualization of ureteral segment on IVU and CTU
- if there is still clinical concern for evaluating the collecting system after an IVU or CTU, a retrograde pyelogram may be able to better image the segment of ureter
- better characterization of ureteral or pelvicalyceal abnormalities seen on IVU or CTU
- access for brush biopsies of a suspicious area of urothelium
A catheter is placed in the ureter of interest, with its tip positioned at the distal ureter. Water-soluble contrast appropriate for the urinary system is instilled slowly to gently distend the upper collecting system. Spot images are obtained of areas of interest.
Distention of the upper collecting system is painful, so overdistention is avoided. Overdistention also results in pyelosinus and pyelovenous backflow, degrading the image.
The patient may need to be rolled into decubitus positions to fill out the lower pole calyces.
Post void images are obtained.
History and etymology
Retrograde pyelography was the first method devised for imaging the urinary collecting system, and until the development of early IVU agents in the 1930s, it was the only way of imaging the collecting system.