A2-05 ACUTE SUSCEPTIBILITY-WEIGHTED MRI OF HEMORRHAGIC BRAIN LESIONS AND ONE-YEAR NEUROPSYCHOLOGIC OUTCOMES AFTER PEDIATRIC TBI

Acute and longitudinal imaging after TBI reveals evolving injury to the brain. Interpretation of imaging findings is limited by availability of corresponding pathological study. A brain donated through the CNRM THINC study provided the opportunity to connect acute and follow-up MRI to pathology. A 48-year-old man was found unresponsive after a bicycle accident. A right subdural hemorrhage (SDH) prompted urgent hemicraniectomy. The subject was consented and research MRI was obtained on days 2, 7, and 101. The patient expired seven months post-injury. Whole brain images were acquired (7T MRI) after formalin fixation. The brain was sliced and selected for embedding in paraffin based on MRI findings and large format tissue sections were mounted on oversized glass slides. Sections were stained using H&E, LFB H&E, and Perls iron. Using the 20x objective, histopathology sections were digitized with 32,000 image tiles in the entire tissue section using a microscope scanner. The resulting image files were compressed as hierarchical JPEG files and viewed using proprietary software to confirm abnormalities detected on MRI with lesions identified on the histological section from the tissue specimen. In addition to SDH and subarachnoid hemorrhages, MRI showed temporal lobe contusions, linear-appearing hemorrhagic lesions in bilateral frontal lobes, microbleeds, and meningeal injury. Based on this evidence, the superior frontal gyrus was chosen as the region of interest. The results demonstrate use of acute MRI findings to target regions of interest for pathology. In-vivo imaging revealed a complexity of injury: pre-existing, primary injury due to acute event, and secondary progressive injury. From pathology alone, it would be difficult to reconstruct the timing of injury. Our approach integrates clinical data along with clinical and postmortem MRI that improves interpretation of the pathological progression.