From the Guidelines
CT urography with both nephrographic and excretory phases is the gold standard technique for diagnosing ureteral rupture. This imaging modality is preferred due to its ability to provide detailed images of the urinary tract, allowing for the identification of contrast extravasation, urinoma formation, perinephric or retroperitoneal fluid collection, and hydronephrosis proximal to the injury site 1. The excretory phase, which typically occurs 5-20 minutes after contrast administration, is crucial for visualizing the ureters and detecting any injuries.
When performing a CT urogram, it is essential to include non-contrast, arterial, venous, and delayed excretory phases to ensure that the entire urinary tract is evaluated. This comprehensive approach is necessary because ureteral injuries are often associated with other abdominal or pelvic trauma. The use of CT urography has largely replaced traditional intravenous pyelography (IVP) due to its superior sensitivity, ability to evaluate surrounding structures, and capacity to detect subtle injuries that might be missed on other imaging modalities.
Key findings suggestive of ureteral rupture on CT urography include:
- Contrast extravasation
- Urinoma formation
- Perinephric or retroperitoneal fluid collection
- Hydronephrosis proximal to the injury site These findings are critical for diagnosing ureteral rupture and guiding further management, which may include surgical intervention or minimally invasive techniques such as percutaneous nephrostomy tube placement or stent placement 1.
In comparison to other imaging modalities, CT urography is preferred due to its high sensitivity and ability to evaluate the entire urinary tract. While other studies may suggest the use of IV contrast-enhanced abdominal/pelvic CT with delayed imaging, the most recent and highest-quality study recommends CT urography with both nephrographic and excretory phases as the gold standard technique for diagnosing ureteral rupture 1.
From the Research
Role of Computed Tomography (CT) in Diagnosing Ureteral Rupture
- Computed Tomography (CT) is a crucial diagnostic tool for identifying ureteral rupture, with high sensitivity and informative results 2, 3, 4, 5, 6.
- CT scans can detect ureteral injuries, urinomas, and other complications associated with ureteral rupture, such as hydronephrosis and abscess formation 3, 4, 5.
- The use of intravenous contrast-enhanced CT and delayed scanning can help establish the diagnosis of ureteral injury and urinoma, obviating the need for additional invasive imaging studies or unnecessary exploration 2, 4, 5.
- CT appearance of urinomas caused by ureteral injuries can vary, including confined water-density fluid collections, free fluid, or both, with extravasation of contrast from the ureter observed on early or delayed scans 5.