Postmortem MRI Evaluation of Maceration Degree of Deceased Fetus

We studied the possibilities of postmortem MRI for assessing the degree of maceration and determining the duration of intrauterine fetal death. Postmortem radiological and pathoanatomic study of the bodies of 38 stillbirths who died antenatally (main group, n=31) and intranatally (control group, n=5), who were born at gestational periods of 22-40 weeks was performed. Before the autopsy, MRI was performed in standard T1 and T2 modes. The tissue of the liver, kidney, brain, femoral muscle, lung, and skin in the hip, abdomen, and skull were studied on T1- and T2-weighted images (WI), followed by calculation of the of MR signal intensity ratio in T2- and T1-WI (SIR). The duration of intrauterine fetal death was determined based on the results of autopsy and analysis of histological preparations. It was found that the calculated values of SIR depended on the evaluated organ and the duration of intrauterine fetal death. Unfortunately, the revealed dynamics of changes in SIR does not allow unambiguous assessment of the severity of maceration processes and, accordingly, the time of fetal death due to its non-linear nature. Nevertheless, the use of SIR indicators of several organs and areas of the body makes it easier to determine the duration of intrauterine fetal death and, hence, to clarify the links of thanatogenesis of the stillborn. The advantages of post-mortem MRI compared to autopsy include non-invasive nature of the study, the possibility of archiving and subsequent multiple delayed analysis of tomograms, as well as the speed of MRI analysis, in contrast to microscopic stage of pathological examination associated with the need to prepare histological preparations.