Postmortem liver hypostases in newborns: radiation and pathological characteristics

BACKGROUND: During pathological and forensic autopsies, the bodies of the deceased are examined to identify nonspecific cadaveric changes. These changes include internal hypostases, which are characterized by the redistribution of blood in tissues and organs under the influence of gravity [1, 2]. Such postmortem hypostases reflect the age of death, but they also complicate the differential diagnosis of lifetime pathological processes and lesions with nonspecific cadaveric changes [3, 4]. Postmortem magnetic resonance imaging represents an objective and noninvasive method of investigation, particularly in cases of neonatal death characterized by relative immaturity of organs and tissues. It may therefore prove to be a promising approach to visualize and evaluate cadaveric hypostases [5, 6]. AIM: The aim of this study was to investigate the manifestations of cadaveric hypostases in the liver of deceased neonates, with a focus on the impact of postmortem period duration. This was achieved through the use of postmortem magnetic resonance imaging and morphologic examination. MATERIALS AND METHODS: The study was based on a comprehensive postmortem radiology and pathological anatomical examination of the bodies of 62 newborns and infants who died at the age of 1.5 hours to 49 days. The subjects were selected to exclude those with developmental anomalies and liver diseases. A postmortem magnetic resonance imaging examination was conducted on a 3T Siemens Magnetom Verio apparatus, followed by a subsequent pathological and anatomic autopsy. The T1- and T2-weighted images were evaluated to determine the presence and severity of the magnetic resonance signal intensity gradient line in the ventral (superior) and dorsal (inferior) regions of the liver tissue. Following the autopsy, tissue samples were obtained from the ventral and dorsal regions of the liver, and subsequently subjected to microscopic analysis of hematoxylin and eosin-stained preparations. RESULTS: The results of postmortem magnetic resonance imaging have enabled the establishment of the radiation characteristics and histological changes in liver tissue caused by cadaveric hypostases. The most notable manifestation of cadaveric hypostases in the liver at postmortem magnetic resonance imaging is the change in magnetic resonance signal intensities in the above and below-located regions of the organ, accompanied by the emergence of a signal intensity gradient. This gradient reflects the location of the body after death and varies depending on the duration of the postmortem period. The signal intensity gradient was more frequently observed on T1-weighted images compared to T2-weighted images. Histological examination of liver tissue preparations revealed an increase in the size of sinusoids and a decrease in the area of hepatic beams, which was observed to progress with increasing age at death and was expressed to a greater extent in the lower liver region. These changes are undoubtedly a morphologic substrate of radiation characteristics. CONCLUSIONS: The specific characteristics of cadaveric liver hypostases, as revealed by postmortem magnetic resonance imaging and morphological study, should be taken into account when analyzing the results and determining the links of thanatogenesis of dead newborns.