Urine leaks and urinomas: diagnosis and imaging-guided intervention

Urine leaks from the kidney, ureter, bladder, and urethra most commonly result from trauma. Urinomas may be occult initially and may lead to complications such as abscess formation and electrolyte imbalances if not promptly diagnosed and appropriately managed. Radiologists play a key role in diagnosing urine leaks and determining their cause and extent. Contrast material-enhanced computed tomography (CT) with delayed imaging, CT cystography, and retrograde urethrography are the diagnostic imaging studies of choice. Studies such as intravenous pyelography, antegrade and retrograde pyelography, renal scintigraphy, and imaging-guided needle aspiration may play complementary diagnostic roles. In some instances, the role of the radiologist ends with the diagnosis of urine leaks, after which patients are treated conservatively or perhaps surgically. Uncomplicated renal urine leaks, extraperitoneal urinary bladder rupture, and type 1 urethral injuries are generally managed conservatively. Urine leaks that require more extensive, imaging-guided treatment can usually be managed safely and effectively with a combination of percutaneous urinoma drainage catheters, percutaneous nephrostomy catheters, ureteral stents, and bladder drainage. In the appropriate setting, use of these management options may reduce urinoma-related complications and limit or totally eliminate the need for urologic surgery.