Technical and interpretive pitfalls of postmortem CT: Five examples of errors revealed by autopsy

Image acquisition of dead bodies, particularly using postmortem computed tomography (PMCT), has become common in forensic investigations worldwide. Meanwhile, in countries such as Japan which have an extremely low rate of autopsy, PMCT is being increasingly used in the clinical field to certify the cause of death (COD) without performing an autopsy or toxicological tests, even in cases of unnatural death. Additionally, these PMCT images are predominantly interpreted by clinical personnel such as emergency physicians or clinicians who are not trained in PMCT interpretation and who work for the police, that is, the so-called police doctors. Many potential pitfalls associated with the use of PMCT have been previously described in textbooks and published papers, including the pitfalls of not performing a complete forensic pathology investigation, and the use of physicians without appropriate PMCT training to interpret PMCT and direct death investigation and certification. We describe five examples in which apparent misdiagnosis of COD based on PMCT misinterpretation was revealed by autopsy. Here are the five examples of errors: (1) Postmortem changes were misinterpreted as COD, (2) resuscitation effects were misinterpreted as COD, (3) COD was determined after an incomplete examination, (4) fatal findings caused by external origin were wrongly interpreted as ‘of internal origin’ based on PMCT, and (5) non-fatal findings on PMCT were wrongly interpreted as fatal. Interpretation of PMCT by appropriately trained physicians and an accompanying complete forensic investigation, including autopsy when indicated, is necessary to prevent significant errors in COD determination and related potential adverse medicolegal consequences.     

Abdominal Stab Wounds with Tension Pneumopericardium Confirmed by Autopsy and Postmortem Computed Tomography

We present the first report of pneumopericardium observed by autopsy and on postmortem computed tomography (PMCT) images. The subject was a woman who died of self‐inflicted stab wounds to the abdomen. The PMCT scan revealed air in the pericardial sac, a “flattened heart” sign, and retroperitoneal hemorrhage. Medicolegal autopsy revealed two abdominal stab wounds near the xiphoid process that had cut the apical pericardium and adjacent diaphragm and liver. Examination of the open thorax confirmed that the pericardial sac was distended with air. The wound extended to the abdominal aorta, causing retroperitoneal hemorrhage. PMCT images showed that the pneumopericardial volume was 133 mL. We believe that cardiac tamponade occurred resulting from the tension pneumopericardium; however, the effects were mitigated by hypovolemia secondary to the retroperitoneal hemorrhage as well as obstructive shock. Therefore, the cause of death appears to have been low‐pressure cardiac tamponade.     

Olanzapine‐Induced Fatal Ketoacidosis with Pneumomediastinum and Subcutaneous Emphysema

We report a case of fatal olanzapine‐induced ketoacidosis in which pneumomediastinum (PM) and subcutaneous emphysema (SE) were detected on postmortem computed tomographic (CT) images. A man in his forties was found in a state of cardiopulmonary arrest with profuse perspiration, and 50 empty capsules of olanzapine (10 mg) and flunitrazepam (1 mg) were found in his room. The major findings of postmortem CT prior to autopsy were PM and SE from the lower half of the face to the height of the first rib. The results of autopsy, biochemical tests, and toxicological analyses indicated the cause of death to be fatal ketoacidosis induced by olanzapine intoxication. No injuries, medical interventions, or particular diseases were evident, suggesting that PM and SE were caused by ketoacidosis. Our findings indicated that toxicological analyses should be performed when PM and SE are detected on CT images.     

Sudden Death from Cardiopulmonary Arrest on Arrival of a Patient with Pulmonary Tuberculosis: A Case Diagnosed by Postmortem CT and Autopsy

Sudden death due to massive hemoptysis during management of tuberculosis occurs in a considerable number of patients. However, when massive airway hemorrhage occurs in a patient in whom tuberculosis has not been confirmed and a blood is not apparent externally on the face/body, it is difficult to immediately identify the cause of death as airway obstruction by tuberculous bleeding in the airway. We encountered an 83‐year‐old Japanese woman with her medical history included treatment of tuberculosis in her 20s who was in cardiopulmonary arrest on arrival (CPAOA), and the cause of sudden death could not initially be identified. Postmortem CT (PMCT) and autopsy revealed that the cause of sudden death was airway obstruction/asphyxia by tuberculous massive airway hemorrhage. Identification of the cause of death facilitated a subsequent active contact investigation and led to prevention of secondary tuberculosis infection.     

Can computed tomography replace or supplement autopsy?

Postmortem computed tomography (PMCT) has been integrated into the practice of many forensic pathologists. To evaluate the utility of PMCT in supplementing and/or supplanting medicolegal autopsy, we conducted a prospective double-blind comparison of abnormal findings reported by the autopsy pathologist with those reported by a radiologist reviewing the PMCT. We reviewed 890 cases: 167 with blunt force injury (BFI), 63 with pediatric trauma (under 5 years), 203 firearm injuries, and 457 drug poisoning deaths. Autopsy and radiology reports were coded using the Abbreviated Injury Scale and abnormal findings and cause of death (COD) were compared for congruence in consensus conferences with novel pathologists and radiologists. Overall sensitivity for recognizing abnormal findings was 71% for PMCT and 74.6% for autopsy. Sensitivities for PMCT/autopsy were 74%/73.1% for BFI, 61.5%/71.4% for pediatric trauma, 84.9%/83.7% for firearm injuries, and 56.5%/66.4% for drug poisoning deaths. COD assigned by reviewing PMCT/autopsy was correct in 88%/95.8% of BFI cases, 99%/99.5% of firearm fatalities, 82.5%/98.5% of pediatric trauma deaths, and 84%/100% of drug poisoning deaths of individuals younger than 50. Both autopsy and PMCT were imperfect in recognizing injuries. However, both methods identified the most important findings and are sufficient to establish COD in cases of BFI, pediatric trauma, firearm injuries and drug poisoning in individuals younger than 50. Ideally, all forensic pathologists would have access to a CT scanner and a consulting radiologist. This would allow a flexible approach that meets the diagnostic needs of each case and best serves decedents' families and other stakeholders.     

Postmortem Computed Tomography in Firearm Homicides: A Retrospective Case Series,

Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner’s office that occurred during 2016. Autopsies were performed or supervised by board-certified forensic pathologists who reviewed the PMCT scans prior to autopsy. PMCT scans were re-evaluated by a forensic radiologist blinded to the autopsy findings and scored by body region (head–neck, thoracoabdominal, and extremities). Injury discrepancies were scored using a modified Goldman classification and analyzed with McNemar’s test. We included 60 males and 20 females (median age 31 years, range 3–73). Based on PMCT, 56 (79.1%) cases had injuries relevant to the cause of death in a single body region (24 head–neck region, 32 thoracoabdominal region). Out of these 56 cases, 9 had a missed major diagnosis by PMCT outside that region, including 6 extremity injuries visible during standard external examination. Yet all had evident lethal firearm injury. We showed that PMCT identifies major firearm injuries in homicide victims and excludes injuries related to the cause of death in other regions when a single body region is injured. Although PMCT has a known limited sensitivity for soft tissue and vascular pathology, it can be combined with external examination to potentially reduce or focus dissections in some of these cases depending on the circumstances and medicolegal needs.     

Traumatic false aneurysm of descending aorta with aortoesophageal fistula

We report a case of traumatically induced false aneurysm with secondary bacterial aortitis of the descending aorta and fistula formation between the aorta and esophagus. This lesion was diagnosed at autopsy and caused death in a 68-year-old female 19 years after an automobile accident. Aortoesophageal fistula (AEF) formation as a result of any cause is rare. To our knowledge, this is the second reported case of traumatic aortic aneurysm as a result of an automobile accident with subsequent AEF formation.     

Massive systemic fat embolism detected by postmortem imaging and biopsy*

Postmortem computed tomography (pmCT) and pmCT angiography (pmCTA) provide a minimally invasive method to determine the cause of death. Postmortem image-guided biopsy allows for precise sampling of histological specimens. This case study describes the findings of lethal systemic fat embolism (FE) on whole-body unenhanced pmCT, pmCTA, and image-guided biopsy, with autopsy and histopathologic correlation. Unenhanced pmCT revealed a distinct fat level on top of sedimented layers of corpuscular blood particles and serum in the arterial system and pulmonary trunk. Subsequent pmCTA showed reproducible results, and image-guided biopsy confirmed fatal FE. pm CT/pmCTA combined with image-guided biopsy established the cause of death as right heart failure as a result of systemic fatal FE prior to autopsy. All imaging findings were consistent with traditional autopsy and histological specimens. This unique case demonstrates new imaging findings in massive, fatal FE and highlights that postmortem imaging, supplemented by image-guided biopsy, may detect the cause of death prior to traditional autopsy.     

Fatal bilateral pneumothoraces after electroacupuncture treatment: A case report and literature review

Acupuncture is practiced as a complementary medicine worldwide. Although it is considered a safe practice, pneumothorax is one of its most common serious complications. However, there have been few reports of deaths due to pneumothorax after acupuncture treatment, especially focused on electroacupuncture. We report an autopsy case of a man in his 60s who went into cardiopulmonary arrest and died immediately after receiving electroacupuncture. Postmortem computed tomography (PMCT) showed bilateral pneumothoraces, as well as the presence of numerous gold threads embedded subcutaneously. An autopsy revealed two ecchymoses in the right thoracic cavity and a pinhole injury on the lower lobe of the right lung, suggesting that the needles had penetrated the lung. There were marked emphysematous changes in the lung, suggesting that rupture of bullae might also have contributed to bilateral pneumothoraces and fatal outcome. The acupuncture needles may have been drawn deeper into the body than at the time of insertion due to electrical pulses and muscle contraction, indicating the need for careful determination of treatment indications and technical safety measures, such as fail-safe mechanisms. This is the first case report of fatal bilateral pneumothoraces after electroacupuncture reported in the English literature. This case sheds light on the safety of electroacupuncture and the need for special care when administering it to patients with pulmonary disease who may be at a higher risk of pneumothorax. This is also the first report of three-dimensional reconstructed PMCT images showing the whole-body distribution of embedded gold acupuncture threads, which is unusual.     

Diesel fumes do kill: a case of fatal carbon monoxide poisoning directly attributed to diesel fuel exhaust with a 10-year retrospective case and literature review*

While it is known that diesel fuel combustion engines produce much lower concentrations of carbon monoxide (CO) than gasoline engines, these emissions could certainly generate lethal ambient concentrations given a sufficient amount of time in an enclosed space and under suitable environmental conditions. The authors report a case of CO poisoning which was initially referred for autopsy as a presumed natural death of a truck driver found in the secure cab of a running diesel tractor trailer truck. Completion of the preliminary investigation ascribed death to complications of ischemic heart disease (IHD), pending toxicological analysis that included quantification of CO. When the toxicology results showed lethal blood COHbg, the cause of death was re-certified as CO intoxication secondary to inhalation of (diesel) vehicular exhaust fumes. Because of the unique source of fatal CO intoxication in this case, the contributory IHD and the possible contaminants in the putrefied blood, a 10-year retrospective review was conducted on all nonfire related CO deaths autopsied (n = 94) at the Office of the Chief Medical Examiner in Louisville, KY from 1994 to 2003. For validation of the COHbg detection method used by the Kentucky Office of Forensic Toxicology (KYOFT), blood samples from these cases along with controls were submitted to three laboratories using various analytical methods yielding no statistically significant differences. Lastly, an extensive literature review produced no scientifically reported cases of fatal CO poisoning attributed to diesel fuel exhaust.     

Hemoperitoneum due to rupture of a subserosal vein overlying a uterine leiomyoma

Uterine leiomyoma is the most common tumor in women of reproductive age, but rarely does it lead to fatal hemoperitoneum. We present an autopsy case in which the cause of death was massive hemoperitoneum due to rupture of a subserosal vein overlying a uterine leiomyoma. We report the case of a 28-year-old Japanese woman who had tuberous sclerosis and was gravida 0, para 0. She had a uterine leiomyoma leading to dysmenorrhea. Autopsy revealed a pinhole-sized rupture of a subserosal vein superficial to the leiomyoma that resulted in fatal hemoperitoneum. Rupture of a subserosal vein overlying a uterine leiomyoma may cause sudden and unexpected death.     

Suicidal shot in the mouth with an unmodified blank cartridge pistol

In the medicolegal literature reports of suicides with weapons designed for self-defence, especially gas pistols, are rare. We report on a suicide of a 54-year-old woman who fired a fatal shot in her mouth with an unmanipulated blank cartridge pistol, make R?hm RG 8, calibre 8 mm. The autopsy findings (lips and mucosa of the buccal vestibule without injuries, but extensive lesions of the tongue and the middle and rear third of the smooth palate) suggest that the shot was fired - as observed by a witness - with the barrel of the weapon inside the oral cavity. Both macroscopic inspection and histological investigations excluded the possibility that death was caused by an injury of the brain, in particular the brain stem. The immediate cause of death was deep aspiration of chyme with concurrent aspiration of blood.     

Death due to neurogenic shock following gastric rupture in an anorexia nervosa patient

We report a case of fatal gastric rupture discovered after death, which developed due to a bulimic attack of a 19-year-old woman suffering from anorexia nervosa. An autopsy revealed an acute gastric dilatation and rupture without commonly observed ischemic damage of gastric wall structures. However, it may be difficult to determine the cause of death despite the marked findings. The death as a consequence of neurogenic shock accounts for all the results of gross examination and histologic analysis. This case is the first reported case of fatal gastric rupture of an anorectic patient discovered after death.     

Fatal attacks of zoo animals on humans--a case report

Media reports about fatal work accidents in zoos caused by zoo animals seem to appear in increasing numbers all around the world. In many cases the cause of such an accident can only be clarified by a detailed reconstruction of the event in combination with the autopsy results. This applies particularly in cases where no eyewitnesses were present. This report is about the case of a musk ox that killed its keeper, in which the fatal accident could be completely reconstructed.     

死后尸体CT在法医学鉴定中的应用价值初探

目的 对不同类型案件中的死者进行死后尸体CT扫描和常规尸体解剖,探索PMCT在法医学鉴定中的应用价值.方法 对7例因不同原因死亡的个体进行全身PMCT扫描,随后进行系统的尸体解剖,通过比较两种方法检测的结果,分析PMCT与传统尸体解剖在不同类型案件中应用的优点和不足.结果 在7个案例中,尸体上总共检出67处阳性发现.其...     

Fatal Intoxication with Toluene Due to Inhalation of Glue

Two cases of fatal intoxications with toluene due to glue sniffing are described. In case 1, the autopsy did not indicate cause of death, while in case 2, the cause of death was determined to possibly be due to mechanical asphyxia by drowning. As the decedents had a history of glue sniffing, toxicological analyses were performed. Using gas chromatography with flame ionization detector and gas chromatography/mass spectrometry (GC/MS) with headspace method, toluene was detected in biological samples. Toluene ranged from 3.81 to 20.97 μg/g, with the highest concentrations observed in liver and brain (13.82–20.97 μg/g) in both cases. Based upon this data, the cause of death in both cases was determined to be toluene poisoning. Toxicological investigations are extremely important and should be considered mandatory in all deaths thought to be due to volatile substance abuse, as well as all deaths that are thought to be due to poisoning in young people.     

The Role of Postmortem Computed Tomography in the Evaluation of Strangulation Deaths

We explored the value of postmortem computed tomography (PMCT) to augment autopsy in evaluating strangulation fatalities. A literature search identified 16 studies describing autopsy findings in 576 deaths and two studies describing autopsy and PMCT findings in six deaths. Similar cases were identified from our institution, yielding 130 deaths with autopsy findings and 14 deaths with both autopsy and PMCT findings. The presence of laryngohyoid fracture and soft tissue hemorrhage was compared from autopsy and autopsy+PMCT cases. The detection rates of fractures in autopsy and autopsy+PMCT cases were not significantly different. PMCT identified all fractures observed at autopsy and five fractures not identified. While PMCT may not detect soft tissue injuries in decomposed remains or subtle internal hemorrhages in neck injury, it is equally able to detect bony injuries as autopsy and might surpass autopsy in detecting subtle fractures. We conclude PMCT is useful to supplement autopsy in strangulation cases.     

Tuberculous Abdominal Aortic Aneurysm with Alimentary Tract Hemorrhage: A Case Report with Medico-legal Implications

An autopsy case of sudden death induced by alimentary tract hemorrhage was presented,which was caused by the unexpected rupture of clinically unrecognized tuberculous abdominal aortic aneurysm(TAAA).The initial diagnosis was made of the syndrome of coronary heart disease and hypertensive disease.The detailed autopsy showed that the alimentary tract hemorrhage was caused by a sudden rupture of the mass after posture changing was ascertained as the cause of death.The diagnosis of TAAA was determined by the autopsy findings.Analysis for the medical dispute of TAAA was described,and the difficulty of the diagnosis and medico-legal implications were also discussed.     

Sudden death of an alcoholic elderly man with acute esophageal necrosis (black esophagus)

We report a fatal case of acute esophageal necrosis (black esophagus) in an elderly male with alcohol abuse who was found dead with coffee-ground vomiting. A postmortem examination revealed severe anemia and marked black coloring of the esophagus from the upper to the bottom end. This was accompanied by histologic evidence of extensive mucosal necrosis. Alcohol abuse and esophagitis-related vomiting were both considered to be factors that led to the acute fatal esophageal necrosis. The cause of death was undetermined. We discuss the possible role of acute esophageal necrosis in the cause of sudden death.