CTurography

CT urography, often referred to as CTU, is a computed tomography imaging protocol specifically designed to evaluate the urinary tract from the kidneys to the bladder. It combines anatomic detail with functional information by visualizing the renal parenchyma, collecting system, ureters, and bladder after administration of iodinated intravenous contrast.

Indications for CT urography include the evaluation of gross or microscopic hematuria, flank pain suggesting stones or obstruction, suspected urothelial carcinoma, renal masses, and staging of urothelial cancers. The examination commonly employs multiphase imaging, typically including a non-contrast phase, one or more contrast-enhanced phases (such as nephrographic or corticomedullary), and an excretory phase when contrast is present in the collecting system. Some protocols use split-bolus techniques or single-pass acquisitions to reduce overall radiation exposure.

Technique and safety considerations: CT urography is performed on multidetector CT scanners with intravenous iodinated contrast. Pre-procedure assessment of renal function and allergy history is recommended, given the risks of contrast-induced nephropathy and hypersensitivity reactions. The study offers high sensitivity for stones, obstruction, and urothelial lesions but entails radiation exposure and potential contrast-related complications. Image interpretation focuses on stone burden and location, renal cortex enhancement, drainage of the collecting system, hydronephrosis, ureteral trajectory, and any filling defects that may indicate tumors.

Alternatives to CT urography include magnetic resonance urography and ultrasound in selected patients. Advances aim to reduce radiation dose and optimize contrast usage while maintaining diagnostic accuracy.