A Multimodal MRI Study in Mild Traumatic Brain Injury: Correlation of Imaging Features with Clinical Symptoms (S11.002)

Objective: To identify features from multimodal MRI data that correlate with clinical symptoms in a mild traumatic brain injury (mTBI) population, with the goal of predicting outcomes. Background: The pathology underlying neurocognitive change after mTBI is poorly understood. Multimodal MRI was used to study the impact of mTBI to the functional and structural organization of the brain. In this study, global, local, and network-specific metrics were extracted from MRI data and correlated to clinical symptoms. Design/Methods: 86 uncomplicated mTBI subjects and 26 controls were recruited. All subjects and controls underwent neurological examination and MRI scans - resting state fMRI (rs-fMRI), T1, T2 FLAIR, diffusion, and perfusion imaging on GE MR750 3T scanners. mTBI subjects were evaluated and scanned at four encounters: 3 days, 7 days, 1 month, 3 months post injury. Controls were scanned twice, one week apart. Pipelines were developed for analysis of rs-fMRI, diffusion, and volumetry of brain structures. Functional and structural networks were computed, and connectivity metrics extracted. The multishell diffusion data allowed computation of radial and orientational quantities, including diffusional kurtosis (DK, a measure of axonal integrity), fiber tractography, and conventional diffusion tensor imaging metrics. These imaging features were correlated with clinical symptom severity score using the SCAT2. Results: Voxel and network-based fMRI metrics (eg fractional amplitude of low frequency fluctuations, p<0.02) were found to correlate with symptom scores. A subset of functional networks displayed broader spatial spread in mTBI subjects than in controls. Whole white-matter DK and FA histograms did not correlate significantly with symptoms; voxel-based analysis is underway (40 subjects). Finally, decreased whole brain, hippocampus, thalamus, caudate, and amygdala volumes correlated with symptom scores only at encounter 4 (p<0.05). Conclusions: A longitudinal, multimodal MRI study in mTBI population was described and statistically significant correlations between clinical measures and select MRI metrics reported. Disclosure: Dr. Marinelli has nothing to disclose. Dr. Chebrolu has nothing to disclose. Dr. Gallenberg has nothing to disclose. Dr. Gupta has nothing to disclose. Dr. Joel has nothing to disclose. Dr. Li has nothing to disclose. Dr. Lo Castro has nothing to disclose. Dr. Madhavan has nothing to disclose. Dr. Middione has nothing to disclose. Dr. Mullick has nothing to disclose. Dr. Prastawa has nothing to disclose. Dr. Ravishankar has nothing to disclose. Dr. Shankaranarayanan has nothing to disclose. Dr. Sperl has nothing to disclose. Dr. Tan has nothing to disclose. Dr. Worters has nothing to disclose. Dr. Zhang has nothing to disclose. Dr. Niogi has nothing to disclose. Dr. Tsiouris has nothing to disclose. Dr. Miranda has nothing to disclose. Dr. Shetty has received personal compensation for activities with GE Healthcare as a medical advisory board member.