CLINICAL PEARLS AND PITFALLS Ureteral injuries are often missed during the initial evaluation with less than 50% of patients diagnosed within 24 hours of presentation Avulsion of the ureter should be suspected when the CT urogram (10-minute delayed imaging after IV contrast administration) demonstrates extravasation of contrast material and nonfilling of the affected ureter CT findings suggestive of renal pelvis or ureteral injury include medial perirenal extravasation of contrast material, a circumrenal urinoma, and the lack of opacification of the ureter distal to the injury However, CT scan has been shown to be poorly sensitive for ureteral injury, identifying only 33% of cases in some series In case in which suspicion for ureteral injury is high, urologic consultation is necessary as retrograde pyelogram is a more reliable examination and offers the potential opportunity for therapeutic intervention Current Evidence Blunt trauma usually involves the UPJ Disruption of the ureter from the renal pelvis results from stretching of the ureter by sudden hyperextension of the trunk Traditionally, this injury has been described more often in children Penetrating injuries may occur at any point along the length of the ureter and are associated with injuries to other intra-abdominal organs in up to 90% of cases Stab wounds rarely cause ureteral injuries Ureteral injuries can occur iatrogenically during surgical procedures involving the retroperitoneum as the ureters may be obscured by bleeding or fibrosis While these situations occur far less common in children than adults, a high suspicion should be maintained in patients presenting with ongoing symptoms after retroperitoneal surgery, most commonly gynecologic, colorectal, vascular, or urologic procedures Clinical Considerations Clinical Recognition Trauma to the ureter should be suspected in patients presenting with fracture of the transverse process of a lumbar vertebra Pelvic fracture, hip fracture, lower rib fracture, splenic laceration, liver laceration, and diaphragmatic rupture have also been reported in association with ureteral injuries Gunshot wounds with a bullet course through the retroperitoneum should also prompt a high level of suspicion