Investigation of the applicability of virtual gastroscopy based on postmortem computed tomography to detect changes in the stomach, along with reports of three rare cases.

Postmortem computed tomography is now being used more commonly for routine forensic investigation. The use of 3D reconstruction techniques including virtual gastroscopy is effective and also improves the speed of interpretation, recognition, and description of specific clinical conditions. However, it has been unclear whether postmortem virtual endoscopy could be applicable for medicolegal autopsy or whether it could complement pathological examination at autopsy. Here, we investigated the applicability of postmortem virtual gastroscopy by reviewing 295 medicolegal autopsy cases seen at our institution, and found four cases in which the technique had been able to demonstrate features corresponding to changes that were evident at autopsy. Thus,postmortem virtual gastroscopy would have only rarely been effective forvisualizing any change in the stomach in such cases. In addition, we describe in detail three of those cases in which virtual gastroscopy had been able to visualize changes in the stomach, including a gastric ulcer, a polyp, and the presence of foamy fluid, which were all verified at autopsy. In those cases, virtual gastroscopy was useful for understanding features in the stomach of the deceased, which were revealed by axial images of the abdomen, to forensic pathologists who were not familiar with PMCT 2D images. Taken together, our findings suggest that postmortem virtual gastroscopy might help facilitate clear, straightforward sharing of information about PMCT images of complex anatomical structures among radiologists and forensic pathologists, as well as non-medical professionals with a limited knowledge of anatomy and physiology.

Tattoo image composed of radiopaque deposits demonstrated by postmortem computed tomography.

Postmortem computed tomography (PMCT) is becoming used more commonly in routine forensic investigation. CT is sensitive for detection of metal foreign bodies. Here we report a case of suicide due to self-ignition of kerosene that the victim had poured over herself. Prior to autopsy, PMCT detected tiny radiopaque particles arranged in a row in the surface of the back and either thigh, together with a series of similar particles under the skin lateral to the breasts or the bilateral inguinal region. At autopsy, external examination revealed third-degree burns involving charred tissues all over the body except for the head. Tattoos were visible on the back and on either thigh. The tattoos had colored designs, and the red portions corresponded to the radiopaque particles in the surface of the body. Internal examination demonstrated swelling of the axillary and inguinal lymph nodes, which corresponded to the radiopaque particles. A wave length-dispersive X-ray spectroscopy revealed deposition of mercury and titanium in the inguinal lymph nodes. Thus, it was plausible that the ink could have contributed to the radiopaque particles found by PMCT in the surface of the back and thighs, as well in the lymph nodes. The present case was able to provide clues for interpretation of radiopaque particles revealed by PMCT in the surface of the body.

Use of postmortem computed tomography to retrieve small metal fragments derived from a weapon in the bodies of victims in two homicide cases.

Postmortem computed tomography (PMCT) is becoming a commonly used modality in routine forensic investigation. Mechanical injuries including lacerations, incisions, stab wounds and gunshot wounds frequently contain foreign bodies that may have significant value as clues in criminal investigations. CT is a sensitive modality for detection of metal foreign bodies that may be associated with injuries to the victim in cases of homicide or traffic accidents. Here we report two cases in which PMCT was able to act as a guide to forensic pathologists for retrieval of metal fragments in the corpses of the victims, the retrieved fragments then being used to validate the confessions of the assailants through comparison with the knife and the crowbar, respectively, that had been used in the crimes. In these cases, the small metal fragments retrieved from the corpses of the victims with the aid of PMCT were decisive pieces of evidence confirming the circumstances of the crimes. These cases illustrate how PMCT can be used to complement the findings of classical autopsy for integrative investigation of corpses with injury.

Usefulness of coronary postmortem computed tomography angiography to detect lesions in the coronary artery and myocardium in cases of sudden death.

Coronary postmortem computed tomography angiography (coronary PMCTA) has been introduced as a routine examination procedure for autopsy at our department. Here, we reviewed eight autopsy cases in which apparent histopathological changes including acute myocardial infarction (AMI), anomalous aortic origin of a coronary artery (AAOCA), hypertrophic obstructive cardiomyopathy (HOCM) and acute myocarditis were involved in the cause of death. For investigation of the coronary artery and shape of the heart, coronary PMCTA was valuable in detecting narrowing or obstruction of coronary artery in AMI, indicating an anomalous aortic origin of the left coronary artery in AAOCA, and demonstrating septal hypertrophy and intracavitary obstruction in HOCM. However, it was debatable whether the hypervascularity demonstrated by coronary PMCTA in the case of acute myocarditis was more prominent than the vascular images obtained in other cases without inflammation. Thus, coronary PMCTA appeared to be useful not only for detection of coronary artery stenosis, but also for indicating other distinctive changes involved in AAOCA and HOCM.

Postmortem computed tomography evaluation of fatal gas embolism due to connection of an intravenous cannula to an oxygen supply.

An 84-year-old man who had suffered from chronic obstructive pulmonary disease accompanied by moderate pneumonia as well as gastric cancer with liver metastasis was found dead by a nurse, who noticed that the patient's intravenous catheter in the left forearm had been erroneously connected to an oxygen supply in his hospital room, leading to infusion of oxygen into a vein. Postmortem CT scanning demonstrated multiple accumulations of gas in the pulmonary artery, the right atrium and ventricle, as well as the left subclavian and brachiocephalic veins, corresponding to the route that the infused gas would have taken to the heart and pulmonary artery. Conventional autopsy revealed the presence of gas in the right ventricle. These findings suggested that the immediate cause of death was a gas embolus due to oxygen that had entered the cardiopulmonary circulation via the intravenous catheter. This case highlights the usefulness of postmortem imaging as an aid to conventional autopsy for demonstrating gas embolism.

Use of postmortem computed tomography angiography to detect vascular injuries accompanying skull base fracture.

A 58-year-old woman who had presented for upper gastrointestinal barium examination accidently slipped from the movable bed, and her head became compressed between the end of the bed and the side wall. She suffered massive bleeding from her nose and ear followed by cardiac arrest, and subsequent attempts at cardiopulmonary resuscitation failed. A medicolegal autopsy was performed to reveal the cause of death, as part of the investigation of the accident. During the autopsy, postmortem cerebral CT angiography was carried out by injection of 5% gelatin-barium emulsion as a radiopaque contrast medium into the bilateral common carotid arteries, demonstrating transudation of the contrast medium into the right acoustic meatus and the sphenoidal sinus cavity. Considering that the body appeared anemic and that PMCTA suggested vascular injuries, the cause of death was definitively determined to be hemorrhagic shock due to injuries to the right internal carotid artery, accompanied by skull base fracture. Postmortem CT angiography played an important role in confirming that the vascular injuries had been responsible for the bleeding, as the lesions could not be fully confirmed by native CT or macroscopic examination.

Use of postmortem coronary computed tomography angiography with water-insoluble contrast medium to detect stenosis of the left anterior descending artery in a case of sudden death.

A 40-year-old man was found dead on a sidewalk in an expressway parking area one hour after he had entered the area on a motorcycle. A medicolegal autopsy was performed to reveal the cause of this sudden and unexpected death. Postmortem coronary CT angiography after introduction of 5% gelatin-barium emulsion as a radiopaque contrast medium into the heart demonstrated a significant arterial luminal filling defect in the left anterior descending (LAD) coronary artery. Macroscopic and microscopic examinations revealed that a thrombus had become deposited on ruptured plaque within the LAD artery, and that a small amount of the contrast medium was present between the thrombus and the vessel endothelium. These histological findings were consistent with incomplete occlusion of the LAD artery in the 3D reconstructed image. The cause of death in this case was definitively determined to be ischemic heart disease. Postmortem angiography played a role in screening of a vascular lesion that was subsequently verified by histology to have been responsible for sudden and unexpected death.

Intestinal obstruction in a mentally retarded patient due to pica.

A 40-year-old mentally retarded Japanese man was admitted at rehabilitation facility for handicapped persons and found dead in his bed. His neonatal period was complicated by seizures, and he had a medical history of schizophrenia. A postmortem computed tomography scan suggested an intestinal obstruction, but the cause was unknown. To clarify the cause of death, a medicolegal autopsy was carried out. The gastrointestinal tract was found to contain copious amounts of cloth pieces. A diagnosis of intestinal obstruction secondary to pica of clothes was made. Despite still being an essentially neglect condition; mental retardation is cause to significant burden to the patient, his relatives and caregivers and the whole society. Moreover, people with mental retardation may be at increased risk for potentially self-injury due to ingestion of non-eating substance or incongruent intake of eating substances, which may on turn lead to severe or even life-threatening medical and surgical complications as herein reported. Specific attention also to pica in mentally-retarded patients with sudden, severe, gastrointestinal events, should therefore be placed in order to prevent potential death or otherwise severe chronic consequences, ideally aiming at enhancing the early recognition and multi-disciplinary management of those psychological stressors or triggers potentially responsible for pica too.

Brain fragility can be estimated by its putrefactive signs on postmortem computed tomography.

Along with time after death, postmortem computed tomography (PMCT) of the brain can reveal sequential changes. In the present study, we investigated the relationship between brain rigidity and advanced postmortem changes such as intravascular gas production, cerebral settling or cerebral liquefaction on PMCT. We then examined the findings of PMCT as an indicator of successful macroscopic examination of arbitrary brain slices at classical autopsy. The association between these advanced postmortem changes and the validity of macroscopic brain examination was investigated in 149 cases that were examined by PMCT at our department prior to autopsy in the period from September 2011 to December 2013. We found that the postmortem changes, classified into four stages, generally reflected the fragility of the brain. Thus, it is likely that PMCT findings of advanced postmortem changes are able to indicate decreased brain rigidity ahead of autopsy. These findings support the idea that PMCT could be used as a guide by forensic pathologists for suitable handling of a fragile brain, thus enhancing the quality of autopsy.

Combination of postmortem mass spectrometry imaging and genetic analysis reveals very long-chain acyl-CoA dehydrogenase deficiency in a case of infant death with liver steatosis.

CASE HISTORY: A 3-month-old infant was found dead in his bed. A postmortem computed tomography (CT) scan suggested fatty attenuation in the liver parenchyma, but no other potentially fatal changes were found. To clarify the cause of death, a medicolegal autopsy was carried out. AUTOPSY FINDINGS: Internal examination confirmed the presence of liver steatosis as well as hepatomegaly. There were no other significant findings including encephalitis or brain edema. MASS SPECTROMETRY ANALYSIS: To clarify the mechanism underlying lipid accumulation in the liver, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) analysis was conducted. This indicated a significant accumulation of C14:1 acylcarnitine in the liver of the deceased, suggesting very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. GENETIC ANALYSIS: To find the cause of the VLCAD deficiency, genetic analysis of the responsible gene, acyl-CoA dehydrogenase, very long chain (ACADVL), was performed. This revealed two novel mutations that may have accounted for the disease. CONCLUSION: A combination of these data revealed that the liver steatosis in this case might have been caused by VLCAD deficiency based on genetic mutations of ACADVL. Thus, the deceased might have been vulnerable to energy crisis and sudden infant death. The present findings show that MALDI-IMS analysis as well as genetic analysis can be useful for elucidating the cause of death.

An integrated teaching method of gross anatomy and computed tomography radiology.

It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench-side (OsiriX on iPod touch or iPad), which enabled "pixel-to-tissue" direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses.

Use of postmortem computed tomography to reveal acute subdural hematoma in a severely decomposed body with advanced skeletonization.

An 81-year-old man was found dead 1 month after he had disappeared following a visit to a hot spring resort in early autumn. The body showed severe postmortem changes with advanced skeletonization from the head to the abdomen as well as putrefactive and autolytic changes in the remaining tissues. The thoracic and abdominal organs had been lost. Naked eye examination revealed soft tissue injuries accompanied by ragged edges and characteristic punctures with no signs of vitality, suggesting that these injuries had been due to postmortem animal scavenging. However, bruises were prominent on the anterior parts of both lower extremities. Postmortem computed tomography (PMCT) scan demonstrated subdural hematoma over the right cerebral hemisphere, although the brain itself had undergone putrefactive and autolytic changes. Subsequent autopsy confirmed the presence of a 140 g acute subdural hematoma, which would likely have been fatal. This case illustrates that PMCT is able to yield important information about possible cause of death, even in a partially skeletonized body.

Use of postmortem computed tomography to reveal an intraoral gunshot injuries in a charred body.

A 53-year-old man was found dead after a fire at his residence had been extinguished. Although a pistol was recovered beside the body, external examination was unable to indicate any gunshot wound because of severe charring of the body. Postmortem computed tomography (CT) scan performed prior to autopsy suggested an entrance gunshot wound in the posterior pharynx with loss of soft tissue and an internal bullet path through the right anterior and posterior parts of the occipital bone. Autopsy revealed an entrance gunshot wound with hemorrhage in the soft tissue of the posterior pharynx, massive contusion of the right occipital lobe, and subarachnoid hemorrhage in the right temporal lobe, both occipital lobes and the superior surface of the left cerebellar hemisphere, thus being consistent with the findings of postmortem CT. A carboxyhemoglobin concentration of 5% in blood from the cadaver was consistent with the lack of soot deposition from the larynx to the bronchus. These observations confirmed that death had been caused by an intraoral gunshot resulting in severe brain damage, before the body had been burned.

A case of fatal drug intoxication showing a high-density duodenal content by postmortem computed tomography.

A 22-year-old woman was found dead in her bed, and subsequent postmortem examination was performed using ordinary methods such as external examination, Triage®, and computed tomography (CT) scan which demonstrated a high-density content of the duodenum. Autopsy and quantitative analysis of drugs present in the GI tract showed that high amounts of radiopaque psychotic agents such as fluvoxamine maleate, carbamazepine, and zolpidem tartrate had been responsible for the high-density profile of the duodenum. Postmortem quantitative analysis of drugs in the blood suggested that death had been caused by fatal intoxication with fluvoxamine maleate. Thus, postmortem CT could offer an opportunity to suspect drug intoxication due to radiopaque psychotic agents such as chloral hydrate, phenothiazine, bromovaleryl urea, fluvoxamine maleate, and probably zolpidem tartrate, although it is neither a specific nor a quantitative test for drugs. Therefore, postmortem CT happened to provide clues to investigation of drug intoxication in the present case.