The diagnosis and prognosis of mild traumatic brain injury (mTBI) is a challenge in the emergency setting. The advanced MRI techniques, including susceptibility weighted imaging (SWI), diffusion tensor imaging (DTI), and MR spectroscopy imaging (MRSI), have been reported being sensitive to subtle changes of the brain after mTBI. However, there is a lack of investigation on the role of advanced MRI in mTBI detection in emergency settings. The objective of our work is to investigate the role of advanced MR imaging techniques for mTBI at acute stage.
Ten mTBI patients, meeting the definition by American College of Rehabilitation Medicine, were recruited in emergency setting in our Level-1 trauma center. Ten aged- and gender-matched healthy controls were also recruited for comparison. All patients were scanned in our 3 Tesla Siemens VERIO magnet with 32-channel head coil.
Among 10 mTBI patients, three of them (30%) had positive CT findings with extra-axial bleeding or injury. SWI detected six of them (60%) with parenchymal injury, including those three CT-positive patients. Furthermore, DTI consistently detected abnormally lower fractional anisotropy (FA) areas (p<0.05) in major white matter tracts that appear normal in structural imaging. Specifically, DTI tract-based spatial statistics (TBSS) analysis consistently reported abnormally lower FA values (p<0.05) in the splenium of corpus callosum (CC) among 4 patients (40%). Voxel-based analysis detected abnormally lower FA values (p<0.05) in superior corona radiata, in addition to CC. MRSI also detected abnormally higher glutamate/glutamine signals in fronto-parietal subcortical white matter among 2 patients (20%). Collectively, three advanced MRI detected abnormalities in 8 out of 10 mTBI patients (80%).
Our data showed that a comprehensive use of three techniques could significantly improve the detection of mild TBI in acute setting. This finding demonstrates a great potential of advanced MRI to assist decision making of mTBI management in the acute setting.