Diffusion imaging of whole, post-mortem human brains on a clinical MRI scanner

• Published in: NeuroImage (Orlando, Fla.) Vol. 57; no. 1; pp. 167 - 181
• Main Authors: Miller, Karla L., Stagg, Charlotte J., Douaud, Gwenaëlle, Jbabdi, Saad, Smith, Stephen M., Behrens, Timothy E.J., Jenkinson, Mark, Chance, Steven A., Esiri, Margaret M., Voets, Natalie L., Jenkinson, Ned, Aziz, Tipu Z., Turner, Martin R., Johansen-Berg, Heidi, McNab, Jennifer A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2011; Elsevier Limited; Academic Press
• Subjects: Anisotropy; Autopsy; Brain; Brain - physiopathology; Brain Mapping - methods; Brain research; Cortex; Diffusion Magnetic Resonance Imaging - methods; Diffusion tensor imaging; Forensic science; Human; Humans; Image Interpretation, Computer-Assisted - methods; Magnetic resonance imaging; Neuroimaging; Post mortem; Scanners; Sectioning; Spinal cord; Studies; Tissue Fixation; Tractography; United Kingdom > UK; Human; Brain; Post mortem; Tractography; Diffusion tensor imaging
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2011.03.070

Diffusion imaging of post mortem brains has great potential both as a reference for brain specimens that undergo sectioning, and as a link between in vivo diffusion studies and “gold standard” histology/dissection. While there is a relatively mature literature on post mortem diffusion imaging of animals, human brains have proven more challenging due to their incompatibility with high-performance scanners. This study presents a method for post mortem diffusion imaging of whole, human brains using a clinical 3-Tesla scanner with a 3D segmented EPI spin-echo sequence. Results in eleven brains at 0.94×0.94×0.94mm resolution are presented, and in a single brain at 0.73×0.73×0.73mm resolution. Region-of-interest analysis of diffusion tensor parameters indicate that these properties are altered compared to in vivo (reduced diffusivity and anisotropy), with significant dependence on post mortem interval (time from death to fixation). Despite these alterations, diffusion tractography of several major tracts is successfully demonstrated at both resolutions. We also report novel findings of cortical anisotropy and partial volume effects. ► Acquisition and processing protocols for diffusion MRI of post-mortem human brains. ► Effect of post-mortem and scan intervals on diffusion indices. ► Tractography in post-mortem human brains. ► Radial diffusion anisotropy in cortical gray matter.