Postmortem CT investigation of skeletal and dental maturation of the fetuses and newborn infants: a serial case study.

Physical maturation involving bones and teeth is a classic indication of fetal maturity in forensic practice, for which radiological examination is effective. The present study preliminarily investigated the efficacy of postmortem computed tomography (PM-CT) in estimating the gestational age of fetuses (n = 3) and newborn infants (n = 4), compared with plain radiography. Body length and weight estimated in reconstructed CT images approximated the measured values, providing additional data of body mass volume and fat development. The diaphyses of humerus and femur, and the epiphyseal ossification centers of femur and calcaneus were more easily identified and accurately measured in CT images than in plain radiographs. The developmental stage of deciduous teeth was also clearly identified. PM-CT was useful to evaluate the physical maturity of infants.

Cardiothoracic ratio in postmortem chest radiography with regard to the cause of death.

It is difficult to examine the intact in situ status of thoracic organs, including the heart and lungs, after opening the chest at autopsy. The present study investigated the pathological diagnostic significance of the cardiothoracic ratio (CTR) with regard to heart and lung weight in postmortem plain chest radiography. The pathological diagnostic significance of the CTR in postmortem plain chest radiography using serial forensic autopsy cases of adults (>19 years of age, n=367, within 72 h postmortem) was retrospectively investigated. In natural deaths, CTR was larger for heart diseases, and was smaller for pulmonary infection and gastrointestinal bleeding, showing correlations to the heart weight except in cases of hemopericardium. In traumatic deaths, CTR was larger in cases of fire fatality and acute methamphetamine intoxication, and varied in cases of blunt injury, showing correlations to the heart weight. However, CTR was smaller for sharp instrument injury and drowning, independently of the heart weight. These findings suggest that postmortem CTR (median, 55.6%, measured using a mobile X-ray apparatus) primarily depends on the heart weight, but is substantially modified during the process of death: the CTR may be enlarged by cardiac dilatation due to terminal congestive heart failure, but may be reduced by inflated lungs in drowning or hypovolemia due to fatal hemorrhage. CTR showed a mild correlation to the right diaphragm level, which was also related to the cause of death, but was independent of the left diaphragm level. Plain chest radiographic findings may also be helpful in investigating the pathophysiology of death, and are to some extent comparable with clinical findings. This also suggests the potential usefulness of postmortem CT and MRI for analysis of terminal cardiac function.

[Significance of postmortem computed tomography in forensic autopsy and its possible issues].

Postmortem imaging (PMI) including computed tomography (CT) and magnetic resonance imaging (MRI) has become a familiar procedure in forensic casework. We investigated a short term impact of postmortem CT(PM-CT) in routine forensic autopsy cases at our institute during a period of 9 months (n = 121, fetus--92 year-old, 7 h--years postmortem), comparing to autopsy findings. In identification, PM-CT was useful for matching skeletal/dental characteristics, superimposing, and detection of foreign materials. However, conventional X-ray was often more effective for detection of small metallic foreign bodies. In pathomorphology, PM-CT partly demonstrated important findings for determining the immediate cause of death, which were confirmed by autopsy, but interpretation to the underlying/initiating/preceding causes of death or contributory factor(s) was mostly difficult or impossible. However, accumulated PM-CT data were useful for retrospective evaluation and review of autopsy findings. These experiences indicate that PMI is useful for radiographic screening and documentation, to be included in supplementary procedures, employing knowledge and experiences of forensic autopsy.

Analyses of cardiac blood cells and serum proteins with regard to cause of death in forensic autopsy cases.

To investigate hematological and serum protein profiles of cadaveric heart blood with regard to the cause of death, serial forensic autopsy cases (n=308, >18 years of age, within 48 h postmortem) were examined. Red blood cells (Rbc), hemoglobin (Hb), platelets (Plt), white blood cells (Wbc), total protein (TP) and albumin (Alb) were examined in bilateral cardiac blood. Blood cell counts, collected after turning the bodies at autopsy, approximated to the clinical values. Postmortem changes were not significant for these markers. In non-head blunt injury cases, Rbc counts, Hb, TP and Alb levels in bilateral cardiac blood were lower in subacute deaths (survival time, 1-12 h) than in acute deaths (survival time <1 h). Wbc counts of left cardiac blood were significantly higher for non-head injury than for head injury in subacute deaths. In fire fatality cases, Plt count was markedly higher with an automated hematology analyzer than by using a blood smear test, suggesting Rbc fragmentation caused by deep burns, while increases in Wbc count and decreases in Alb levels were seen for subacute deaths. For asphyxiation, Rbc count, Hb, TP and Alb levels in bilateral cardiac blood were higher than other groups, and TP and Alb levels in the right cardiac blood were higher for hanging than for strangulation. These findings suggest that analyses of blood cells and proteins are useful for investigating the cause of death.

Possible use of nasal septum and frontal sinus patterns to radiographic identification of unknown human remains.

The aim of the present study was to examine the combined use of the nasal septum and frontal sinus pattern for systemic radiographic identification of unknown human remains and the limitations. Postmortem skull radiographs were collected in 209 forensic autopsy and 163 clinical cases. In total cases, a combined use of the nasal septum deviation patterns (straight, left, right, sigmoid, reverse sigmoid and rare types) and the frontal sinus patterns (aplasia, symmetry, left or right dominant asymmetry in combination with the number of lobulations) achieved a classification of at least 204 different types (incidence up to 5%). Comparison of the ante- and postmortem films (n=24) gave an identical result in about 75%. The cases of inconsistency suggested the influences of the positioning in radiographic examination, the quality of radiographs and the complicated structures of the nasal septum and frontal sinus as possible causes of missing identity.