How important is susceptibility-weighted imaging in mild traumatic brain injury?

Mild traumatic brain injury (mTBI) is a public health problem that is recognized as a 'silent epidemic' in its late stages due to undiagnosed axonal damage rated 13 and above on the Glasgow Coma Scale (GCS). Injury-related microhemorrhages often cannot be detected on computed tomography (CT) scans and conventional magnetic resonance imaging (MRI). This study aims to investigate whether susceptibility-weighted imaging is feasible in mTBI patients.

Fifty-eight patients with GCS scores of 14 and 15 and with symptoms of brief mental fogs, impairment of concentration, memory loss, headache, dizziness, or imbalance after brain injury were examined at the emergency service. A brain CT scan and MRI containing diffusion-weighted and susceptibility-weighted imaging (SWI) sequences were performed on the patients whose symptoms did not seem to alleviate after the sixth hour. Thirteen patients were excluded from this study because of advanced age, diabetes, a history of hypertension or its chronic sequelae, or acute cerebrovascular disease; 45 patients were included in this study.

The patients' CT results were normal, and no diffusion restrictions were observed. The SWI revealed microhemorrhages in seven patients (15.6%). Five of these patients had hyperintense areas in conventional sequences corresponding to the hemorrhages spotted in the SWI. In three of the five patients, these pockets of hemorrhages were higher in number and size in comparison with conventional in the SWI sequence.

Susceptibility-weighted imaging, which can be used to assess the presence and severity of microhemorrhages due to diffuse axonal injury, is recommended for determining the cause of symptoms in patients with mTBI, to continue targeted treatment and prevent complications that may develop.