Synopsis

Keywords: Cardiovascular: Angiography, Body: Urogenital, Body: Body

In acute trauma cases, CT is preferred for its accessibility and speed, though concerns arise over radiation and contrast agents. MR imaging supplements CT, particularly in assessing traumatic lesions. For chest trauma, MR aids in blunt thoracic aortic injury assessment, guiding management decisions. It's also useful for chest wall fracture assessment, revealing occult rib fractures. In abdominal trauma, MRCP helps detect pancreatic and biliary duct injuries; Gd-EOB-DTPA also aids in bile duct injury evaluation. MR imaging is valuable in pelvic injuries due to its excellent tissue contrast. Considering radiation exposure, MR imaging would be preferred in pediatrics and pregnant patients.

In cases of acute trauma, CT is the primary modality of choice for imaging evaluation(1). The overwhelming advantage of CT lies in its accessibility, speed of examination, and the ease of whole-body scanning. Additionally, the focused assessment with sonography in trauma (FAST) is a point-of-care ultrasound protocol developed to assess for hemoperitoneum and hemopericardium(2, 3). Due to its accessibility and patients' unstable conditions, MR examination is not appropriate for initial evaluations. However, there are concerns regarding radiation exposure and potential side effects of iodinated contrast agents in contrast-enhanced CT. Furthermore, there are areas where MR imaging proves useful due to the limitations of CT imaging(4, 5). MR imaging should be used for work-up of traumatic lesions, adding information for deciding further treatment strategy. Moreover, in pediatric or pregnant patients, where minimizing radiation exposure is crucial, the application of MR imaging may be considered(5).

Chest:
Blunt thoracic aortic injury (BTAI) is a rare but lethal entity, most commonly occurring in motor vehicle collisions(6). While contrast-enhanced CT is typically utilized for assessment of the aorta and other organs, MR imaging examinations can be beneficial when the use of iodinated contrast agents is challenging. The management strategies for BTAI include medical therapy, thoracic endovascular aortic repair (TEVAR), and surgical repair. Especially with device development, TEVAR has emerged as the dominant therapy for BTAI(6). MR imaging can be used for the follow-up examination after interventions; especially patients treated by TEVAR require long-term follow-up, raising concerns about radiation exposure on CT(7). Depending on the materials of the stent graft, endoleak evaluation after TEVAR is feasible. Furthermore, functional analysis (flow analysis) of the thoracic aorta may add prognostic information after TEVAR(8).
Chest wall fractures can commonly occur; radiographs are usually the first choice imaging modality used in suspected chest wall fractures. However, MR imaging may provide a potential complementary tool for the assessment of chest wall fractures. Early MR imaging after work-related chest trauma can identify the source of pain, mainly radiographically occult rib fractures(9).
Abdomen:
In abdominal trauma cases, the evaluation of pancreatic and biliary duct injuries via magnetic resonance cholangiopancreatography (MRCP) can provide valuable information for determining treatment plans(4, 10). In cases with traumatic pancreatic injury, CT may be limited for the evaluation of main pancreatic duct. MRCP allows for detection of pseudocysts communicating with the main pancreatic duct. Gadolinium ethoxybenzyl (Gd-EOB-DTPA) is an MR contrast agent that is approximately 50% taken up by hepatocytes and excreted by the biliary system(11). Although the contrast agent is generally applied to evaluate primary and metastatic liver tumors, it can be also utilized for evaluating bile duct injuries. Gd-EOB-DTPA-MRCP enables adequate detection and localization of bile leakages in postoperative and post-traumatic patients(12).
MR imaging also works for evaluation of indetermined findings on CT by utilizing its superior soft tissue contrast, which include mimickers in the spleen and liver.
Pelvic Region:
Detailed lesion evaluations utilizing excellent tissue contrast are also achievable in pelvic injuries. Role of MR imaging in the management of male urethral injury with or without pelvic fracture has been reported(13). MR imaging provides detailed information on the post-traumatic anatomy, including the urethral gap length and displacement of the prostate. MR imaging is recommended as a second-line imaging examination in cases of scrotal trauma and non-diagnostic ultrasound findings(14)
Others:
MR imaging may be employed for a thorough investigation of incidental findings, usually detected by other imaging modalities, in trauma cases. Cases of chronic expanding hematoma will also be demonstrated.

This presentation aims to outline the imaging workflow in trauma cases, provide examples and case presentations illustrating the indications for MR imaging, thereby introducing the role of MR imaging in trauma care.

Acknowledgements

No acknowledgement found.