n. X-ray examination of the pelvis of the kidney using radiopaque contrast material. Anterograde pyelography is performed by puncturing the renal pelvis directly with a needle through the skin and injecting contrast material. Intravenous pyelography is usually part of an examination of the whole urinary tract (see intravenous urography). Retrograde pyelography is performed after a tube has been inserted through the bladder and up the ureter at cystoscopy. Contrast material is injected up this tube as it is withdrawn and X-ray images taken. All techniques are used to show the anatomy of the renal pelvis and its drainage, as well as to demonstrate the presence of tumours and stones.
Subjects: Medicine and Health.