Fetal brain maceration score on postmortem magnetic resonance imaging vs. conventional autopsy

Background Postmortem fetal magnetic resonance imaging (MRI) has been on the rise since it was proven to be a good alternative to conventional autopsy. Since the fetal brain is sensitive to postmortem changes, extensive tissue fixation is required for macroscopic and microscopic assessment. Estimation of brain maceration on MRI, before autopsy, may optimize histopathological resources. Objective The aim of the study is to develop an MRI-based postmortem fetal brain maceration score and to correlate it with brain maceration as assessed by autopsy. Materials and methods This retrospective single-center study includes 79 fetuses who had postmortem MRI followed by autopsy. Maceration was scored on MRI on a numerical severity scale, based on our brain-specific maceration score and the whole-body score of Montaldo. Additionally, maceration was scored on histopathology with a semiquantitative severity scale. Both the brain-specific and the whole-body maceration imaging scores were correlated with the histopathological maceration score. Intra- and interobserver agreements were tested for the brain-specific maceration score. Results The proposed brain-specific maceration score correlates well with fetal brain maceration assessed by autopsy (τ = 0.690), compared to a poorer correlation of the whole-body method (τ = 0.452). The intra- and interobserver agreement was excellent (correlation coefficients of 0.943 and 0.864, respectively). Conclusion We present a brain-specific postmortem MRI maceration score that correlates well with the degree of fetal brain maceration seen at histopathological exam. The score is reliably reproduced by different observers with different experience.