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Analysis of published data on the possibilities of using postmortem radiation studies in perinatology is carried out and the results of own thanatoradiological studies of the bodies of dead fetuses and newborns are presented. The possibilities of postmortem radiation studies for differential diagnosis of stillborn and deceased newborns, evaluation of the severity of maceration and the time of intrauterine fetal death, detection of pathological changes in the brain and spinal cord, respiratory and digestive organs, in the cardiovascular and urinary systems were demonstrated. It is concluded that postmortem CT has a high diagnostic efficiency in the study of the bone skeleton, free fluid accumulations in serous cavities and gas in the vessels and tissues of dead fetuses and deceased newborns. The advantage of postmortem MRI is more effective visualization of internal organs and soft tissues, which allows assessing their topography and size, as well as identifying a wide range of pathological changes. For a comprehensive objective analysis of the bodies of stillborn and deceased newborns, combined use of both imaging methods (CT and MRI) is required. At the same time, thanatoradiology should be used as a part of a comprehensive pathological study, but not as a substitute for traditional autopsy., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

Using postmortem MRI, we studied the features of the development of internal cadaveric hypostasis in dead newborns. Postmortem radiological and pathoanatomical examination of 62 bodies of newborns and infants who died at the age of 1.5 h to 49 days was carried out. After the death was ascertained, prior to MRI, the bodies were stored in a refrigerator at 4°C in the supine position. Depending on the duration of the postmortem period (2-72 h), all observations were divided into eight groups. Prior to autopsy, an MRI scan was performed in T1 and T2 standard modes, followed by analysis of the presence and severity of the gradient line of the intensity of the MR signal in the liver and lung tissue in the ventral (overlying) and dorsal (underlying) areas, as well as the presence of a gradient of the intensity of the blood signal in the heart cavity and in the aortic lumen. The main manifestations of cadaveric hypostasis in the liver and lungs are changes of the MR signal intensity in the ventral and dorsal regions with the appearance of a horizontal gradient of the MR signal intensity, which reflects the location of the body after death. In the heart cavity and in the aortic lumen, there is also a gradient of the blood signal intensity of various severity with the visualization of two or three of its layers. The revealed features of the MRI signal intensity and, accordingly, the presence of its horizontal gradient depended not only on the MRI mode of the study, but also on the studied organ and the duration of the postmortem period. This should be taken into account when analyzing the results of virtopsy and determining the links of thanatogenesis of dead newborns and infants.

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.

The potentialities of postmortem MRI for differential diagnosis of stillbirth and death of a live newborn are studied. The results of MRI and pathomorphological studies of autopsy material from 20 stillborns dead at weeks 22-40 of gestation (group 1) and 19 newborns dead at the age of 2 h to 36 days (group 2) are analyzed. Control group has been formed from 7 live newborns aged 1-7 days. Postmortem MRI provides an objective quantitative evaluation of the intensity of MR signal in various tissues and regions. Calculation of the proportions of MR signal intensities in the lung tissue and environmental air and/or pleural fluid and the respiration values promotes an objective differential diagnosis of stillbirth and death of a live newborn. These data are expected to facilitate clearing out the circumstances and the direct cause of death. However, postmortem MRI cannot completely replace autopsy with complex macroscopic and microscopic studies of organs and tissues.

We studied the possibilities of postmortem magnetic resonance imaging (MRI) for evaluation of anasarca in newborns. Before the autopsy, MRI in T1 and T2 standard modes was performed, signal intensity tomograms in the subcutaneous tissue were analyzed, and tissue hydration index was calculated. Using 3D reconstruction, we determined the values of hydrothorax, hydropericardium, and ascites, as well as specific volumes of fluid in the abdominal and thoracic cavities. It has been established that postmortem MRI of deceased newborns provides objective quantitative assessment of anasarca, as well as absolute and relative volumes of hydrothorax and ascites, which improves the diagnostic capacities of pathoanatomical autopsy or forensic examination of a corpse and contributes to the determination of tanatogenesis. However, postmortem MRI cannot fully replace traditional autopsy that allows conducting complex macroscopic and microscopic analysis of organs and tissues.

We explored the possibility of using postmortem MRI for the diagnostics of lung hypoplasia associated with innate diaphragmatic hernia in neonates. The main experimental group consisted of 17 newborns with innate diaphragmatic hernia including 10 non-operated newborns and 7 newborns died after surgery for innate diaphragmatic hernia. It was demonstrated that postmortem MRI allows objective quantitative assessment of the absolute and relative dimensions of the lungs in the thoracic cavity and thereby reveals their hypoplasia, which contributes to the determination of tanatogenesis. Surgery for congenital diaphragmatic hernia leads to an increase in the mass and volume of the lungs, but does not always eliminate their hypoplasia.