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.

中文翻译：

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死胎浸渍程度的尸检MRI评价

我们研究了尸检 MRI 用于评估浸渍程度和确定宫内胎儿死亡持续时间的可能性。对 38 例产前（主要组，n=31）和产内（对照组，n=5）死产死胎的尸体进行了尸检放射学和病理解剖学研究，这些死胎出生于 22-40 周的妊娠期。尸检前，MRI 在标准 T1 和 T2 模式下进行。在 T1 和 T2 加权图像 (WI) 上研究肝脏、肾脏、大脑、股骨肌肉、肺和皮肤的臀部、腹部和头骨组织，然后计算 MR 信号强度比T2- 和 T1-WI (SIR)。根据尸检结果和组织学准备分析确定宫内胎儿死亡的持续时间。发现 SIR 的计算值取决于评估的器官和宫内胎儿死亡的持续时间。不幸的是，所揭示的 SIR 变化动态不允许对浸渍过程的严重程度进行明确评估，因此，由于其非线性性质，胎儿死亡时间也不能明确评估。尽管如此，使用多个器官和身体部位的 SIR 指标可以更容易地确定宫内胎儿死亡的持续时间，从而澄清死胎死亡发生的联系。与尸检相比，尸检 MRI 的优势包括研究的非侵入性、存档和随后对断层图像进行多次延迟分析的可能性，以及 MRI 分析的速度，