Medial extravasation of contrast is often seen with UPJ ruptures and no contrast will be seen in the distal ureter on delayed images of complete UPJ avulsion Historically, diagnosis of UPJ injuries was delayed in 50% of cases but routine evaluation of trauma with CT, especially when delayed images are obtained, has increased the initial detection rate to almost 90% Ultrasound The focused assessment by sonography for trauma (FAST) is often used to evaluate trauma patients for abdominal injuries and intra-abdominal fluid collections Despite the availability and low risk nature of sonography, this modality has a low sensitivity (48%) for detecting renal injuries and often overlooks significant damages The use of contrast-enhanced ultrasound has recently been reported to increase the sensitivity to 69%, which is still inferior to the >90% sensitivity of CT Extravasation is also more difficult to visualize on ultrasound Currently used contrast preparations are not well excreted into the collecting system, limiting evaluation in the trauma setting This study is being utilized more often for follow-up of parenchymal injuries, especially in stable patients Intravenous Urography Although almost completely replaced by CT for evaluating stable trauma patients, the intravenous urogram or pyelogram still maintains a role in evaluating the unstable trauma patient taken directly to the operating room The main utility of this modality is to verify the presence of a functioning contralateral kidney The one-shot urogram is performed by giving a mL/kg body weight contrast bolus followed by plain film 10 minutes later Identifying a functional contralateral kidney is important first because every possible attempt should be made to save the injured kidney if it is the only one The injured kidney may lack contrast uptake if there is a major vascular injury or demonstrate a delayed nephrogram due to significant compression from a contained hematoma An abnormal renal outline, displacement of the bowel or ureter, and loss of the psoas margin are all suggestive of renal injury and hematoma Distinctive patterns of contrast extravasation that raise concern of a possible UPJ injury include extravasation medial or circumferential (circumferential urinoma) to the kidney Also, with a complete UPJ disruption, the ipsilateral ureter will lack intraluminal contrast The study is not particularly sensitive for picking up ureteral injuries