A longitudinal study to characterize quantitative MRI changes due to progressive formalin-fixation in whole postmortem human brains
| dc.contributor.author | Shatil, Anwar Shahadat | |
| dc.contributor.examiningcommittee | Kornelsen, Jennifer (Radiology) Moussavi, Zahra (Electrical and Computer Engineering) Essig, Marco (Radiology) | en_US |
| dc.contributor.supervisor | Figley, Chase (Radiology) Matsuda, Kant (Pathology) | en_US |
| dc.date.accessioned | 2017-05-10T16:04:24Z | |
| dc.date.available | 2017-05-10T16:04:24Z | |
| dc.date.issued | 2017-11-29 | en_US |
| dc.degree.discipline | Biomedical Engineering | en_US |
| dc.degree.level | Master of Science (M.Sc.) | en_US |
| dc.description.abstract | Postmortem MRI can be used to reveal important pathologies and establish radiology-pathology correlations. However, quantitative MRI values are altered by tissue fixation. Therefore, the purpose of this thesis was to investigate time-dependent effects of formalin fixation on MR relaxometry (T1 and T2), diffusion tensor (fractional anisotropy, FA; and mean diffusivity, MD), and myelin water fraction (MWF) measurements throughout intact human brain specimens. Two whole, neurologically-healthy human brains were immersed in 10% formalin solution and then scanned at 13 time-points between 0 and 1032 hours. Whole brain maps of longitudinal (T1) and transverse (T2) relaxation times, FA, MD, and MWF were generated at each time-point to illustrate the changes over time, and region-of-interest analyses were performed in eight brain structures to quantify the changes with progressive fixation.Although neither of the diffusion measures (FA nor MD) showed significant changes as a function of formalin fixation, both T1 and T2-relaxation times were significantly decreased, and MWF estimates were significantly increased. These results suggest that T1-relaxation, T2-relaxation and myelin water fraction estimates must be performed very early, or at consistent time-points, in the fixation process to avoid formalin-induced changes compared to in vivo values or between samples, respectively. | en_US |
| dc.description.note | October 2017 | en_US |
| dc.identifier.citation | Shatil, A. S., Matsuda, K. M., & Figley, C. R. (2016). A Method for Whole Brain Ex Vivo Magnetic Resonance Imaging with Minimal Susceptibility Artifacts. Frontiers in Neurology, 7, 208. http://doi.org/10.3389/fneur.2016.00208 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/32247 | |
| dc.language.iso | eng | en_US |
| dc.publisher | Frontiers in Neurology | en_US |
| dc.rights | open access | en_US |
| dc.subject | Ex vivo | en_US |
| dc.subject | Formalin | en_US |
| dc.subject | Fixation | en_US |
| dc.subject | MRI | en_US |
| dc.subject | Neuroimaging | en_US |
| dc.subject | Postmortem | en_US |
| dc.subject | Diffusion | en_US |
| dc.subject | T1 | en_US |
| dc.subject | T2 | en_US |
| dc.subject | Myelin | en_US |
| dc.title | A longitudinal study to characterize quantitative MRI changes due to progressive formalin-fixation in whole postmortem human brains | en_US |
| dc.type | master thesis | en_US |