Hideyuki Hayakawa

Postmortem pulmonary edema: A comparison between immediate and delayed postmortem computed tomography

OBJECTIVE Postmortem CT (PMCT) findings may change with the passage of time after death. The aim of this study was to investigate time-dependent PMCT findings of the lung in order to aid the interpretation of postmortem images obtained at various times. MATERIALS AND METHODS Our subjects were three non-traumatically deceased male subjects (25, 44, and 76 years old) who underwent whole body PMCT scan at two time points: one immediately after death and the other several hours after death but before the autopsy. The causes of death of the subjects were acute cardiac insufficiency (so-called sudden manhood death syndrome, 2 subjects), ischemic heart disease (acute coronary syndrome, 1 subject). The immediate and delayed PMCT findings of the lung were compared, and the differences between them were investigated. RESULTS Compared with immediate PMCT, delayed PMCT showed advanced dependent opacity and consolidation corresponding to congestive pulmonary edema. CONCLUSION PMCT images of the lung change as the time after death increases due to the natural postmortem changes of the corpse. Immediate PMCT is more suitable than delayed PMCT for discerning cause of death. Delayed PMCT reflects the autopsy findings more accurately than immediate PMCT.

Characteristic signal intensity changes on postmortem magnetic resonance imaging of the brain

PurposeWe investigated and identified postmortem changes on magnetic resonance imaging (MRI) of the brain to provide accurate diagnostic guidelines.Materials and methodsOur subjects were 16 deceased patients (mean age 57 years) who underwent postmortem computed tomography (CT), MRI, and autopsy, the latter of which showed no abnormalities in the brain. The subjects underwent CT and MRI 6–73 h after confirmation of death (mean 26 h), after being kept in cold storage at 4°C. Postmortem MRI of the brain was performed using T1-weighted imaging (T1WI), T2WI, fluid attenuated inversion recovery (FLAIR) imaging, and diffusion weighted imaging (DWI) with parameters identical to those used for living persons.ResultsIn all cases, postmortem CT showed brain edema and swelling. Postmortem MRI showed characteristic common signal intensity (SI) changes, including (1) high SI of the basal ganglia and thalamus on T1WI; (2) suppression of fat SI on T2WI; (3) insufficient SI suppression of cerebrospinal fluid on FLAIR imaging; (4) high SI rims along the cerebral cortices and the ventricular wall on DWI; and (5) an apparent diffusion coefficient decrease to less than half the normal value.ConclusionPostmortem MRI of the brain in all cases showed characteristic common SI changes. Global cerebral ischemia without following reperfusion and low body temperature explain these changes.

A column-switching LC/MS/ESI method for detecting tetrodotoxin and Aconitum alkaloids in serum

A liquid chromatography-mass spectrometry-electrospray ionization (LC/MS/ESI) method coupled with a column-switching technique has been developed for the determination of tetrodotoxin (TTX) and Aconitum alkaloids and their metabolites, such as aconitine, mesaconitine, hypaconitine, jesaconitine, benzoylaconine, benzoylmesaconine, benzoylhypaconine and 14-anisoylaconine, in serum. An on-column column-switching technique was employed to analyze TTX and Aconitum alkaloids and their metabolites without pretreatment of the serum. Combination of a multimode column with reversed phases and cation exchange for TTX, and use of a multimode column with reversed phases and a hydrophobic polymer column for Aconitum alkaloids and their metabolites provided successful separation and MS determination in ESI positive mode. A 100 microl serum sample was directly injected into a precolumn. For TTX monitored at m/z 320.1 in the selected ion monitoring mode, the calibration curve was linear within the range 0.1-100 ng/ml and the limit of detection was 0.1 ng/ml. For aconitine, mesaconitine, hypaconitine and jesaconitine, linear calibration curves were obtained up to 500 ng/ml and the limit of detection ranged from 0.2 to 1 ng/ml. For benzoylaconine, benzoylmesaconine, benzoylhypaconine and 14-anisoylaconine, linear calibration curves were obtained up to 500 ng/ml and the limit of detection ranged from 2 to 50 ng/ml. Recoveries from serum samples were within the range 78-119% for all the compounds studied.

Nontraumatic postmortem computed tomographic demonstration of cerebral gas embolism following cardiopulmonary resuscitation

PurposeThe aim of this study was to investigate cerebral gas embolism (GE) on nontraumatic postmortem CT (PMCT), regarding its frequency, location (arterial or venous), and causes.Materials and methodsOur subjects were 404 nontraumatically deceased patients who had been in a state of cardiopulmonary arrest on arrival at our emergency room. PMCT was performed within 2 h of the confirmation of death.ResultsCardiopulmonary resuscitation (CPR) was performed on 387 of the 404 subjects; and of these, cerebral GE was detected in 29 (7.5%) subjects (3 arterial, 25 venous, 1 undeterminable). Cerebral GE was not noted in the other 17 of the 404 subjects who did not undergo CPR. However, there was no significant difference in the incidence of cerebral GE between the subjects who underwent CPR and those who did not. The mechanism of cerebral arterial GE was presumed due to pulmonary barotrauma and/or paradoxical embolism, while the thoracic pump theory was suggested to explain the cerebral venous GE.ConclusionCerebral arterial/venous GE is found in CPR cases on nontraumatic PMCT.

Postmortem Computed Tomography Findings as Evidence of Traffic Accident-Related Fatal Injury

PurposeMost traumatic deaths in Japan are due to nonpenetrating injuries, especially those that result from traffic accidents; however, the autopsy rate of traffic accident-related deaths is only about 5%. We investigated the diagnostic ability of postmortem computed tomography (PMCT) in cases of fatal trauma after traffic accidents.Materials and methodsOur subjects were 78 subjects (59 males, 19 females; mean age 50 years, range 15–87 years) who were brought to our institution in cardiopulmonary arrest on arrival after traffic accidents and died despite resuscitation attempts. PMCT findings of damage to the head, neck, thorax, abdomen, and pelvis were classified into three grades according to the Abbreviated Injury Scale (AIS) severity: A: 1 (minor), 2 (moderate); B: 3 (serious), 4 (severe), 5 (critical); C: 6 (maximum).ResultsThe percentage ratio of A/B/C in 78 head injuries was 32/60/8, in 41 neck injuries 83/5/12, in 76 thorax injuries 5/38/57, in 76 abdominal injuries 70/24/7, and in 76 pelvic injuries 79/21/0, respectively.ConclusionPMCT can detect or presume fatal trauma when diagnosing the cause of death after traffic accidents

An accidental case of aconite poisoning due to Kampo herbal medicine ingestion

An accidental case of aconite intoxication occurred after a patient took a therapeutic dose of Kampo herbal medicine containing Aconiti tuber, Uzu but had used the wrong decoction procedure. The poisoning was likely caused by an increased level of Aconitum alkaloids in the decoction; the patient developed aconite intoxication due to incomplete decoction. Aconitum alkaloid levels in the leftover solution which the patient had drunk and in the decoction extracted from 3g Uzu were determined. It was found that decoction makes the medicine safer to drink. Older individuals, especially those with dementia, have a higher risk of aconite poisoning because they sometimes do not boil the medicine appropriately.

Sudden death as a late sequel of Kawasaki disease: postmortem CT demonstration of coronary artery aneurysm.

Kawasaki disease (KD) is an acute, self-limited vasculitis of unknown etiology that primarily affects the coronary artery (CA) and presents during childhood. The characteristic coronary arterial lesion of KD is an aneurysm. Ischemic heart disease derived from a CA aneurysm is experienced approximately two decades after the onset of acute KD. In recent years, the primary issue of concern has been asymptomatic adults with a CA aneurysm caused by undiagnosed KD. We present a case of sudden death as a late KD sequel in a young adult. A postmortem CT scan revealed a coarse calcification of a left anterior descending CA aneurysm, which was confirmed at the time of autopsy. A postmortem CT scan is useful in cases of sudden death where the detection of a calcified CA aneurysm would suggest to the forensic pathologist that the deceased suffered from a late sequel of KD. The use of screening postmortem CT scans for young people may detect cases of unsuspected CA aneurysms, raising the possibility of untreated KD.

Cerebral Relaxation Times from Postmortem MR Imaging of Adults

PURPOSE We measured T1 and T2 values of cerebral postmortem magnetic resonance (PMMR) imaging and compared the data of cadavers with that of living human subjects. MATERIALS AND METHODS We performed PMMR imaging of the brains of 30 adults (22 men, 8 women; mean age, 58.2 years) whose deaths were for reasons other than brain injury or disease at a mean of 29.4 hours after death. Before imaging, the bodies were kept in cold storage at 4°C (mean rectal temperature, 15.6°C). We measured T1 and T2 values in the brain bilaterally at 5 sites (bilateral caudate nucleus, putamen, thalamus and gray matter and white matter of the frontal lobe) and compared the data of PMMR imaging with that from MR imaging of the corresponding sites in 24 healthy volunteers (9 men, 15 women; mean age, 51.8 years). We also investigated the influence of body temperature on T1 and T2 values. RESULTS Compared with MR imaging findings in the living subjects, PMMR imaging showed significantly shorter T1 values in the caudate nucleus, putamen, thalamus and gray matter and white matter of the frontal lobe and significantly longer T2 values in the gray matter and white matter of the frontal lobe; T2 values in the caudate nucleus, putamen, and thalamus showed no such differences. T1 values correlated significantly with body temperature in all 5 brain sites measured, but T2 values did not. CONCLUSION Compared with findings of cerebral MR imaging in living adult subjects, those of PMMR imaging tended to demonstrate shorter T1 values and longer T2 values. We attribute this to increased water content of tissue, reduced pH, and reduced body temperature after death.

A case of fatal cervical discoligamentous hyperextension injury without fracture: Correlation of postmortem imaging and autopsy findings☆

We present a case of fatal cervical discoligamentous hyperextension injury without fracture. Postmortem computed tomography (PMCT) and postmortem magnetic resonance imaging (PMMRI) disclosed cervical instability and spinal cord injury in the absence of fracture, which was confirmed by autopsy. Cervical discoligamentous injury without fracture may be unnoticeable on PMCT because signs of cervical misalignment change depending on the posture of the neck at the time of postmortem imaging. Because of its greater sensitivity for soft tissue injury, PMMRI is especially useful for detecting pathological changes in cases of death due to cervical discoligamentous injury. In this paper, findings on postmortem imaging for this injury are described in detail and correlated with findings on autopsy.

Immediate non-traumatic postmortem computed tomographic demonstration of myocardial intravascular gas of the left ventricle: effects from cardiopulmonary resuscitation

SummaryAn 87-year-old man was found in a state of cardiopulmonary arrest. Despite cardiopulmonary resuscitation (CPR) for over 1 hour by emergency technicians and physicians, the patient died. Immediate postmortem computed tomography showed cardiovascular gas in the right atrium, right ventricle, and left ventricle. Cardiovascular gas in the left ventricle was located in the myocardium and appeared as linear or branch-shaped suggesting the presence of myocardial intravascular gas. This is the first report describing the appearance and significance of myocardial intravascular gas of the left ventricle as a CPR-related change.