Post mortem evaluation of brain edema using quantitative MRI

The post mortem assessment of brain edema is routinely performed during autopsy by forensic pathologists who evaluate the macroscopically visible signs. In this study, the suitability of magnetic resonance imaging (MRI) for a differentiation between edematous and nonedematous brains was examined as an objective, noninvasive and quantitative rating method. In this study, 22 deceased underwent post mortem in situ MRI prior to regular autopsy. Acquired MRI sequences allowed the computation of the quantitative MRI parameters T1, T2, T2*, fractional anisotropy (FA) and mean diffusivity for the cortex, white matter and deep gray matter separately. Beside the autopsy results, which represent the gold standard for rating brain edema, also the normalized cerebral weight (NCW) was determined by dividing the brain weight by the intracranial volume as developed by Bauer et al. [10]. For further examination of the relation of MRI parameters with the NCW, linear regression models were calculated. The results revealed highly significant correlations of the MRI parameters T2 and FA with the NCW in the cortex. These combinations additionally showed the best fitting results of the linear regression models. In conclusion, quantitative MRI is suitable for differentiating edematous from nonedematous brains by calculating T2 and FA in the cortex. A post mortem in situ MRI scan of the brain can, besides delivering morphological information, add relevant and objective information on the edema status of the brain prior to autopsy or when no autopsy is ordered. (c) 2022 Published by Elsevier B.V. CC_BY_4.0

Automated summary

This study examined the suitability of magnetic resonance imaging (MRI) as an objective, noninvasive, and quantitative method for differentiating edematous and nonedematous brains. The results showed that quantitative MRI, specifically the calculation of T2 and FA parameters, can effectively differentiate edematous brains from nonedematous brains. In addition to providing morphological information, post mortem in situ MRI scans can provide relevant and objective information on the edema status of the brain prior to autopsy or when no autopsy is ordered.