Urography

Urography is a radiologic examination of the urinary tract that uses contrast material to visualize the kidneys, ureters, and bladder. It encompasses several imaging techniques designed to depict anatomy, function, and potential pathology of the urinary tract through excretory or cross-sectional methods.

Historically, intravenous urography (intravenous pyelography) involved injecting iodinated contrast and taking timed X-ray images to outline the renal parenchyma, collecting system, and ureters. Its use has declined with the advent of cross-sectional imaging, but it remains a reference in some settings.

Modern urography includes retrograde urography, in which contrast is introduced directly into the ureter via catheter to evaluate obstructions or stones; voiding cystourethrography to assess bladder and urethral anomalies and vesicoureteral reflux; and CT urography, a CT-based excretory protocol providing detailed anatomic and functional information. MR urography uses magnetic resonance imaging with specialized sequences and sometimes gadolinium contrast to visualize the urinary tract without ionizing radiation and is useful in children or patients needing radiation avoidance.

Indications include evaluation of hematuria, flank pain, suspected urinary tract obstruction, stone disease, congenital anomalies, preoperative assessment, and staging or surveillance of urothelial tumors. Choice of modality depends on the clinical question, patient factors, and availability.

Risks include allergic or nephrotoxic reactions to iodinated or gadolinium contrast, and radiation exposure, particularly with CT-based protocols. Contraindications include contrast allergy, pregnancy considerations, and significant kidney impairment. Ultrasound is often used as an initial, radiation-free alternative or adjunct.