Whole brain analysis of postmortem density changes of grey and white matter on computed tomography by statistical parametric mapping
This study examined the usefulness of statistical parametric mapping (SPM) for investigating postmortem changes on brain computed tomography (CT).
This retrospective study included 128 patients (23 − 100 years old) without cerebral abnormalities who underwent unenhanced brain CT before and after death. The antemortem CT (AMCT) scans and postmortem CT (PMCT) scans were spatially normalized using our original brain CT template, and postmortem changes of CT values (in Hounsfield units; HU) were analysed by the SPM technique.
Compared with AMCT scans, 58.6 % and 98.4 % of PMCT scans showed loss of the cerebral sulci and an unclear grey matter (GM)–white matter (WM) interface, respectively. SPM analysis revealed a significant decrease in cortical GM density within 70 min after death on PMCT scans, suggesting cytotoxic brain oedema. Furthermore, there was a significant increase in the density of the WM, lenticular nucleus and thalamus more than 120 min after death.
The SPM technique demonstrated typical postmortem changes on brain CT scans, and revealed that the unclear GM–WM interface on early PMCT scans is caused by a rapid decrease in cortical GM density combined with a delayed increase in WM density. SPM may be useful for assessment of whole brain postmortem changes.
• The original brain CT template achieved successful normalization of brain morphology.
• Postmortem changes in the brain were independent of sex.
• Cortical GM density decreased rapidly after death.
• WM and deep GM densities increased following cortical GM density change.
• SPM could be useful for assessment of whole brain postmortem changes.
KeywordsComputed tomography Brain Grey matter White matter Postmortem changes
Antemortem computed tomography
Montreal Neurological Institute
Magnetic resonance imaging
Postmortem computed tomography
Statistical parametric mapping
We are grateful to Ms. S. Kodama, Mr. J. Iijima, Ms. Y. Nishiyama, Mr. M. Notsu, Ms. H. Maehara, Ms. Y. Hara, Mr. K. Nakao and Ms. S. Kageyama (Department of Radiology, Shimane University Hospital) for their technical support. The scientific guarantor of this publication is Hajime Kitagaki. The authors of this manuscript declare a relationship with the following company: Kazunori Kawakami is an employee of Fujifilm RI Pharma, Japan. The authors state that this work has not received any funding. Kazunori Kawakami kindly provided statistical advice for this manuscript and has significant statistical expertise. Institutional Review Board approval was obtained. Written informed consent was waived by the Institutional Review Board.
Methodology: retrospective, observational, performed at one institution.