urogram

An urogram is a radiographic study of the urinary tract performed after the administration of a contrast agent, intended to visualize the kidneys, ureters, and bladder. Historically, the term referred to an excretory or intravenous urogram (IVU), also called intravenous pyelography (IVP). Today, urography can be performed using intravenous contrast with X-ray imaging, CT urography, or other contrast-enhanced modalities, and the term describes the imaging series rather than a single image.

Procedure and techniques: A iodinated contrast agent is injected intravenously. Serial radiographs capture the passage of contrast through the urinary tract: an early nephrogram, a pyelogram of the renal pelvis and calyces, imaging of the ureters, and often a post-void film to assess bladder emptying. Retrograde urography may be used when intravenous access is unsuitable or detailed ureteral imaging is needed, with contrast delivered via catheter directly into the urinary tract.

Indications: Urography is used to evaluate hematuria, flank or abdominal pain, suspected obstruction or stone disease, tumors, congenital anomalies, vesicoureteral reflux, and overall renal function and anatomy prior to surgical procedures or transplantation.

Limitations and risks: The examination involves ionizing radiation and the use of iodinated contrast, which carries risks of allergic reactions and potential nephrotoxicity, particularly in compromised renal function. It is generally avoided in pregnancy. Advances in CT urography and MRI urography have expanded imaging options, sometimes replacing older IVU protocols for certain indications.