Daisuke Yajima

Does imaging technology overcome problems of conventional postmortem examination? A trial of computed tomography imaging for postmortem examination.

We used a mobile computed tomography (CT) unit for postmortem examinations of deceased subjects to see how many mistakes on cause-of-death diagnoses were made in Japan. In 5 of 20 cases, the cause of death determined by CT was different from the diagnosis made by superficial postmortem examination. In one case, the superficial examination suggested no trauma, whereas a subdural hematoma was found on cranial CT images. We concluded that postmortem examinations in Japan were not effective when screening for crimes or accidents. Using a mobile CT scanner in postmortem examination may be a viable method of screening for causes of deaths, although it cannot be used as a substitute for autopsy.

Diagnosable and non-diagnosable causes of death by postmortem computed tomography: A review of 339 forensic cases

Postmortem computed tomography (PMCT) is often used to diagnose causes of death, especially in nations with a low autopsy rate. To identify the causes of death that can and cannot be determined by PMCT, imaging findings were reviewed in 339 consecutive forensic autopsy cases. Causes of death could be determined based on PMCT findings alone in 7% of these cases, based on suggestive PMCT findings with additional information in 54%, and could not be determined by PMCT in 38%. PMCT screening may be useful for establishment of some causes of death, including traumatic intracranial hematoma, endogenous intracranial hemorrhage, and some cases of cardiac rupture. Suggestive findings from PMCT in other cases, such as those involving subarachnoid hemorrhage or pericardial hematoma, can lead to misdiagnosis and may be a pitfall of PMCT screening. Causes of death including some cases of cervical cord injuries, asphyxiation, burn, drug intoxication, acute myocardial infarction, and pulmonary thromboembolism cannot be diagnosed using PMCT.

The relationship between cell membrane damage and lipid peroxidation under the condition of hypoxia-reoxygenation: analysis of the mechanism using antioxidants and electron transport inhibitors

We consecutively observed lipid peroxidation and cell membrane damage under the condition of hypoxia‐reoxygenation (H/R) in cells and analyzed their mechanisms by using electron transport inhibitors and an antioxidant. In H/R experiments, lipid peroxidation and cell membrane damage were observed during the hypoxia phase. In the reoxygenation phase, lipid peroxidation stopped, while cell membrane damage did not. An antioxidant, n‐acetylcystein (NAC), and potassium cyanide (KCN) inhibited lipid peroxidation and cell membrane damage, while rotenone did not inhibit either of them. Although antimycin A did not inhibit lipid peroxidation, it inhibited cell membrane damage during the hypoxia phase but not during the reoxygenation phase. These results suggested that lipid peroxidation can affect cell membrane damage as a trigger during the hypoxia phase and the generation of oxidative stress can vary depending on the inhibition locations in the electron transport system. Copyright

Stature estimation in Japanese cadavers using the sacral and coccygeal length measured with multidetector computed tomography

We evaluated the relationship between stature and the length of the sacrum and coccyx using multidetector computed tomography (MDCT) and derived regression equations for stature estimation in the modern Japanese population. Two hundred and sixteen Japanese subjects (110 males and 106 females) who underwent postmortem computed tomography with subsequent forensic autopsy between January 2010 and August 2013 were measured. A sagittal-plane image of the sacrum and coccyx was used. Anterior sacral length (ASL) was defined as the linear distance from the anterosuperior edge of the first sacral vertebra (S1) to the anteroinferior edge of the fifth sacral vertebra (S5), and posterior sacral length (PSL) was defined as the linear distance from the posterosuperior edge of S1 to the anteroinferior edge of S5. Anterior sacrococcygeal length (ASCL) was defined as the linear distance from the anterosuperior edge of S1 to the anteroinferior edge of the last coccygeal vertebra (LCV), and posterior sacrococcygeal length (PSCL) was defined as the linear distance from the posterosuperior edge of S1 to the anteroinferior edge of the LCV. The correlation between stature and each parameter was evaluated by simple regression analysis using Pearson product-moment correlation coefficients. Each parameter was significantly and positively correlated with stature among both males and females. Cadaver stature (CS, cm)=0.39×PSL (mm)+123.70 [Corrected] provided the most accurate stature prediction (R=0.507, SEE=5.83 cm) in males. CS (cm)=0.56×PSCL (mm)+85.29 provided the most accurate stature prediction (R=0.659, SEE=6.68 cm) in females. We conclude that sacral/sacrococcygeal length measured with MDCT is a potentially useful tool for stature estimation, particularly in cases where better predictors such as the long bones are not available.

Application of postmortem 3D-CT facial reconstruction for personal identification.

Abstract:  Postmortem computed tomography (CT) images can show internal findings related to the cause of death, and it can be a useful method for forensic diagnosis. In this study, we scanned a ready‐made box by helical CT on 2‐mm slices in a mobile CT scanner and measured each side of the box to assess whether reconstructed images are useful for superimposition. The mean difference between the actual measurements and the measurements on the three‐dimensional (3D) reconstructed images (3D‐CT images) is 0.9 mm; we regarded it as having no effect on reconstruction for the superimposition method. Furthermore, we could get 3D‐CT images of the skull, which were consistent with the actual skull, indicating that CT images can be applied to superimposition for identification. This study suggested that postmortem CT images can be applied as superimpositions for unidentified cases, and thinner slices or cone beam CT can be a more precise tool.

Stature estimation in Japanese cadavers based on pelvic measurements in three-dimensional multidetector computed tomographic images.

The aim of this study was to examine the feasibility of stature estimation by measuring the pelvic bones of Japanese cadavers using three-dimensional (3D) computed tomography (CT). We assessed 3D reconstructed images of 210 Japanese subjects (108 males, 102 females) who had undergone postmortem CT between May 2011 and November 2013. We defined the linear distance from the anterosuperior margin of the left and right anterior superior iliac spines (ASIS) to the posterior margin of the left and right ischial spines as the LSS and RSS, respectively. We also defined the linear distance from the anterosuperior margin of the left and right ASIS to the anteroinferior margin of the left and right ischial tuberosities as the LST and RST, respectively. The correlation between the cadaver stature (CS) and each parameter (LSS, LST, RSS, and RST) was evaluated using Pearson product–moment correlation coefficients and regression analysis was performed for stature estimation. All four parameters correlated significantly with stature independent of sex, suggesting that they can be used as a tool for stature estimation. The LST had the closest correlation with stature in both sexes.

Evaluation of Computed Tomography as a Screening Test for Death Inquest

Abstract:  The Japanese method of inquest, which depends mostly on external examinations, may misdiagnose a considerable number of accidental deaths and suicides as death by disease. We conducted computed tomography (CT) scans of 80 cases for which police concluded death by disease or natural causes based on police investigations into the circumstances and results from external examinations. The cause of death was clearly determined by CT scan in 17 of 80 cases. Ten cases underwent autopsy after the police suspected criminality based on results of the CT examinations. The results suggest CT scan may be a tool for preventing a number of overlooked crimes and accidents in Japan. However, it cannot be a perfect tool for discerning between death by disease and other causes of death without cooperation from the investigative agencies and subsequent forensic examinations such as autopsy and toxicological tests.

Age estimation by multidetector CT images of the sagittal suture

Closure of cranial sutures progresses with age; therefore, macroscopic assessment of cranial sutures has been used as one method of age estimation. Postmortem computed tomography (PMCT), which many forensic medical departments and institutes have begun to adopt, has the potential to simplify the gathering of information from cranial sutures for both surface and cross-sectional evaluation. To examine the feasibility of age estimation by cross-sectional multidetector computed tomography images of the sagittal suture, PMCT findings of 125 subjects of known age and sex were retrospectively reviewed. The sagittal suture was divided into four segments, and 20 cross-sectional slices from each segment were analyzed. These slices were each categorized by visual evaluation into one of the seven stages defined by Harth et al. according to the degree of closure. The mean stage value of 20 slices was calculated for each segment. We were able to evaluate cross-sectional images of the sagittal suture by PMCT, and a positive correlation between age and closure degree was observed. Despite the prediction interval achieved with this method not being superior to traditional macroscopic or flat-panel CT assessment, multidetector CT is a potentially useful tool, in conjunction with other methods, for age estimation, particularly in adult females and in cases where only a skull is the sole remain.

Detection of varicella-zoster virus DNA in 414 human trigeminal ganglia from cadavers by the polymerase chain reaction: a comparison of the detection rate of varicella-zoster virus and herpes simplex virus type 1.

Investigation of varicella‐zoster virus (VZV) is important epidemiologically, and determination of its prevalence rate in human trigeminal ganglia is important to provide surveillance data. To date, studies on VZV detection in trigeminal ganglia have used specimens obtained from a relatively limited number of cadavers. This study attempted to detect VZV DNA as well as Herpes simplex virus type 1 (HSV‐1) DNA by the polymerase chain reaction (PCR) from 414 samples of trigeminal ganglia obtained from 207 cadavers selected at random. The detection rate was examined to determine whether there were significant differences in the positive rate between the left and right trigeminal ganglia, males and females, and among age groups. A relationship was found between the positive rates for VZV and HSV‐1. VZV DNA was detected in 391 of the trigeminal ganglia (94.4%) and 201 of the cadavers (97.1%) in 121/124 males and 80/83 females. HSV‐1 DNA was detected in 251 of the samples (60.6%) and 134 of the cadavers (64.7%) in 72/124 males and 62/83 females. There was no significant difference for either virus in the detection rates between the left and right trigeminal ganglia and males and females. Age and positivity for HSV‐1, but not VZV, showed a significant relationship. All 134 cadavers positive for HSV‐1 were also positive for VZV. VZV and HSV‐1 become latent in bilateral trigeminal ganglia, and are not affected by gender. The prevalence of HSV‐1 was greater in advanced age, and the HSV‐1‐positive rate was correlated with the VZV‐positive rate. J. Med. Virol. 82:345–349, 2010.

Can cervical spine injury be correctly diagnosed by postmortem computed tomography

We discuss the usefulness of postmortem computed tomography (PMCT) by reviewing cases of cervical spine injury. A merit of PMCT is that it can identify injury that cannot be found on autopsy; however, peculiar defects of it may exist. While PMCT can identify bone fractures, it cannot indicate whether the injury was inflicted while the deceased was still alive or not because of its inability to clearly image bleeding around the fracture. Furthermore, CT often misses some types of cervical spine injuries, such as laceration of an intervertebral disk and incomplete fracture of the cervical spine. On the other hand, cervical spine injury on CT images occasionally has an appearance similar to subarachnoid hemorrhage due to rupture of the cerebral artery, indicating that cervical spine injury can be misdiagnosed as a disease by PMCT. When PMCT is used for screening trauma, caution must be observed regarding its limitations. If the possibility of trauma of the neck or head is not completely ruled out from the personal history of the victim, autopsy is strongly recommended, even when PMCT findings indicate that the cause of death may be due to disease, such as subarachnoid hemorrhage.