|ECR 2018 / C-2016||
|Renal Trauma: Tips for successful imaging and diagnosis|
Renal injury occurs in approximately 5% of all trauma and in 10% of abdominal traumas. In the majority of cases, the renal injury results from blunt trauma (90%) with penetrating injuries comprising only 10% of cases [1,2]. The mechanism of injury in blunt trauma can be due to direct impact or rapid deceleration such as in road traffic accidents (RTAs) or a fall from a height. While the former mechanism will usually result in injury to the renal parenchyma (contusions, haematomas and lacerations), the latter can cause injury at the renal pedicle where it is more mobile within the abdominal cavity.
Renal trauma is more severe in patients with underlying renal abnormalities, both congenital and acquired e.g. horseshoe kidney, cross fused ectopia, pelvic kidney or hydronephrosis. ( Fig. 1 ) In these patients the assessment of renal injury on imaging can also be more challenging.
Imaging plays a vital role in the management of renal trauma. It is now commonly accepted that a conservative approach to management is preferable where possible . Surgical exploration for renal trauma has a high nephrectomy rate . Accurate evaluation of renal injuries on CT can often allow a nonoperative approach and improve patient outcome. Detection and accurate grading of injuries on the imaging findings is therefore of critical importance.
A consensus of international authors summarised the role of imaging in renal trauma as follows :
- Accurately stage the injury
- Identify pre-existing renal pathology
- Document the function/presence of the uninjured kidney
- Identify injuries to other intra-abdominal organ
When discussing imaging in the setting of renal trauma, we are almost exclusively referring to computed tomography (CT). Modalities other than CT have a limited role in the imaging of acute renal trauma. Ultrasonography in the form of a ‘FAST scan’ in the Emergency Department can be useful for identifying free intra-abdominal fluid but does not adequately assess the retroperitoneum and is not sensitive at detecting vascular injuries. MRI is generally not practicable in the setting of acute trauma but may be used for follow up.
Thematically related posters
ECR 2018 / C-1875
What the radiologist should know about the different medical internal and external devices used to treat critically injured patients in the acute trauma setting