Sudden death due to coronary artery dissection associated with fibromuscular dysplasia revealed by postmortem selective computed tomography coronary angiography: A case report.

We present an autopsy case of sudden death due to coronary artery dissection associated with fibromuscular dysplasia (FMD) in a young female patient. Postmortem selective coronary artery computed tomography (CT) angiography revealed dissections of the left anterior descending and left circumflex arteries. These findings were confirmed by subsequent autopsy. Histopathological examination revealed coronary artery FMD, which is considered a risk factor for dissection. To the best of our knowledge, this is the first postmortem radiology-pathology correlation of coronary artery dissection associated with FMD.

Statistical analysis of biomechanical properties of the adult sagittal suture using a bending method in a Japanese forensic sample.

This study examined the mechanical properties of the adult sagittal suture compared with surrounding parietal bones using bending tests and investigated the association between the mechanical properties of the suture and age. We used the heads of 116 Japanese cadavers (76 male cadavers and 40 female cadavers) of known age and sex. A total of 1160 cranial samples, 10 from each skull, were collected. The samples were imaged using multidetector computed tomography, and the sample thickness at the center of each sample (ST) was measured. The failure stress of each sample (FS) was measured by a bending test, and the ratio of failure stress to the square of sample thickness (FS/ST(2)) was calculated. Statistical analyses revealed that the FS and FS/ST(2) values were significantly lower at all suture sites than at all bone sites regardless of sex. There were not significant but slight positive correlations between age and FS and FS/ST(2) values at any suture site in male samples. In female samples, age had significant positive correlations with FS and FS/ST(2) values at the middle suture sites, whereas there were not significant but slight positive correlations between age and FS and FS/ST(2) values at the edges of the suture. Statistical analyses also demonstrated that FS and FS/ST(2) values were significantly greater in male samples than in female samples at the middle suture sites. These findings suggest that the bending strength of the adult sagittal suture is significantly lower than that of surrounding parietal bones. Therefore, avoiding direct impact on cranial sutures may be important for preventing skull fractures and severe complications that can cause death. The results of this study also revealed that the bending strength of the middle sagittal suture significantly increases with age in only female samples, whereas the bending strength is significantly higher in male samples than in female samples at the middle suture sites, indicating the possibility of sex difference in the bony interdigitation of the sutures during childhood.

Stature estimation in Japanese cadavers based on scapular measurements using multidetector computed tomography.

This study assessed the correlation between stature and scapular measurements in a Japanese population, using three-dimensional (3D) computed tomographic (CT) images, and derived regression equations for predicting stature. A total of 194 cadavers (100 males 94 females) underwent postmortem CT (PMCT) and subsequent forensic autopsy in our department between May 2011 and April 2014. Left and right longitudinal scapular lengths (LLSL and RLSL, respectively) and left and right transverse scapular lengths (LTSL and RTSL, respectively) were measured on 3D CT reconstructed images that extracted only scapular data. The correlation between stature and each of the scapular measurements were analyzed using Pearson product-moment correlation coefficients. The four variables correlated significantly with stature, regardless of sex. The LLSL measurement had the lowest standard error of estimation value among all subjects (4.22 cm) and among all females (4.37 cm), whereas the RLSL measurement had the lowest standard error of estimation value among all males (3.75 cm). The results of this study indicate that scapular measurements may be useful for the forensic estimation of the stature of Japanese individuals, particularly in cases where better predictors, such as long bone lengths, are unavailable.

Stature estimation in Japanese cadavers based on the second cervical vertebra measured using multidetector computed tomography.

The purpose of this study was to assess correlations between measurements of the second cervical vertebra (C2) and stature using multidetector computed tomography (MDCT) images, and to develop regression equations for estimating stature in a Japanese population. Measurements were performed on 216 Japanese subjects (116 males and 100 females) who underwent postmortem CT between May 2011 and November 2013. Sagittal images through the center of the C2 were used for assessment. The length from the top of the dens to the anteroinferior point of the vertebral body (DA), the length from the anteroinferior point of the vertebral body to the posterior point of the spinous process (AS), and the length from the top of the dens to the posterior point of the spinous process (DS) were measured. The correlation between stature and each parameter (DA, AS, and DS) was assessed using Pearson product-moment correlation coefficients and regression analysis was performed for stature estimation. All measurements of the C2 were positively correlated with stature regardless of sex. The highest correlation was observed for the DA in all cases, and the lowest correlation was observed for AS in all cases. However, the standard errors of estimate were large. Thus, our study concludes that the size of the C2 as measured with MDCT images may be useful for stature estimation only when better predictors, such as long bones, are unavailable.

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.

Stature estimation based on measurements of the sternal medullary cavity using multidetector computed tomography images of Japanese cadavers.

Stature estimation using a skeleton is important for the medicolegal investigation of unidentified human remains. The aims of this study were to identify a correlation between stature and measurements of the sternal medullary cavity using multidetector computed tomography (MDCT) and derive regression equations for stature estimation in the Japanese population. Measurements were conducted on 215 Japanese subjects (107 males, 108 females) who underwent postmortem computed tomography with subsequent forensic autopsy between May 2012 and January 2014. For assessment, MDCT cross-sections through the mid-point of the first costal facets were chosen. The length of a rising diagonal stroke from the bottom left to the top right of the sternal medullary cavity (RS) and the length of a falling diagonal stroke from top left to bottom right of the sternal medullary cavity (FS) were measured. Statistical analyses indicated that both RS and FS were positively correlated with stature regardless of sex. The correlations were stronger for males than for females. The correlation coefficients for RS were higher than those for FS, and standard errors of estimation calculated by regression analysis using RS were lower than those using FS regardless of sex. Measurement of the sternal medullary cavity using MDCT images may be a potentially useful tool for stature estimation, particularly in cases where better predictors such as long bones are not available.

Spinal cord injuries with normal postmortem CT findings: a pitfall of virtual autopsy for detecting traumatic death.

OBJECTIVE: The purpose of this study was to assess the incidence of spinal cord injuries without radiographic abnormalities (SCIWORA) on postmortem MDCT studies and to characterize this entity in detail. MATERIALS AND METHODS: Data from consecutive autopsies from October 2009 through December 2012 were searched, yielding 30 cases of cervical spinal cord injuries. Two board-certified radiologists interpreted postmortem MDCT images acquired before autopsy. Cases with normal findings were defined as SCIWORA. RESULTS: Postmortem MDCT images in 6 of 30 cases (20%; 95% CI, 8-39%) met SCIWORA criteria. In all these cases, traumatic death was not apparent before CT, the highest injury level was below C3, and fractures were not identified at autopsy. All subjects had occult disk injuries and perivertebral hemorrhage. Potentially fatal CT-detectable injuries to other parts of the body were not seen in five of six SCIWORA cases. CONCLUSION: A substantial proportion of fatal spinal cord injuries are without radiographic abnormalities at CT. Forensic radiologists and other interpreters of postmortem MDCT images must be aware of this entity to avoid excluding spinal cord injuries solely on the basis of postmortem MDCT findings. Special care is necessary in cases of unknown circumstances of death without abnormal CT findings. MRI may be used for further examination in the future, but until then, MDCT cannot replace autopsy for detecting SCIWORA.

Observation of vertebral artery damage using angioscopy in autopsy cases.

The vertebral arteries are important blood vessels that supply the cerebral circulation in conjunction with the internal carotid arteries. In cases of subarachnoid hemorrhage, it is necessary to examine the vertebral arteries as potential sources of bleeding due to blunt trauma (head and neck) or of cerebral embolism that originated on the surface of the damaged intima as a result of hyperflexion or hyperextension. However, a considerable part of the vertebral arterial surface is surrounded by bone, resulting in challenges during examination in a routine autopsy. In this study, angioscopy was used to inspect the vertebral artery intima for damage in cases of neck injury, head injury, or neck strangulation. Intimal damage was detected in 34 out of the total 75 cases. Of the 28 cases with cervical discopathy or fracture, 61% had intimal damage. In addition, postmortem application of computed tomography angiography was performed to identify the injured vessel in a case with traumatic subarachnoid hemorrhage, and a perforated hole was detected using angioscopy, which did not introduce autopsy-related artifacts. Therefore, angioscopy may be a useful and nondestructive method to identify intimal damage in the vertebral arteries during an autopsy.

Postmortem dynamic cerebral angiography for detecting aneurysm and bleeding sites in cases of subarachnoid hemorrhage.

One of the advantages of postmortem imaging is its ability to obtain diagnostic findings in a non-destructive manner when autopsy is either difficult or may destroy forensic evidence. In recent years, efforts have been made to incorporate computed tomography (CT) based postmortem angiography into forensic pathology; however, it is not currently clear how well the modality can determine sites of bleeding in cases of subarachnoid hemorrhage. Therefore, in this study, we investigated the utility of postmortem cerebral angiography using multi-detector row CT (MDCT) by injecting a contrast medium through a catheter inserted into the internal carotid and vertebral arteries of 10 subarachnoid hemorrhage cases. While postmortem MDCT angiography (PMCTA) was capable of detecting aneurysms in a non-destructive manner, it was sometimes difficult to identify the aneurysm and bleeding sites because of a large amount of contrast medium leaking into the extravascular space. To overcome this problem, we developed the novel contrast imaging method "dynamic cerebral angiography," which involves scanning the same area multiple times while injecting contrast medium to enable real-time observation of the contrasted vasculature. Using multiphase contrast images acquired by this method, we successfully captured the moment when contrast medium leaked from the hemorrhage site. This method will be useful for identifying exact bleeding sites on PMCTA.

Trends in forensic autopsy in Chiba prefecture over the past decade.

The death investigation system in Japan is in the midst of a great transformation. As part of efforts to revise this system, in this study we analyzed the reasons the police refer unnatural death cases for forensic autopsy and, from an understanding of the trends of such referrals, we discuss the future direction of handling unnatural deaths in our country. For 1618 forensic autopsy cases handled by the First Investigation Division of Chiba Prefectural Police that were referred to our institution for forensic autopsy between 2003 and 2012, we tallied the number of autopsies by sex, age group, and reason for forensic autopsy for each year and investigated trends in the referrals over time. The results revealed that the number of autopsies increased annually from 2003 to 2012, with a marked increase from 2010. The number of autopsies increased particularly for cases of suspected criminal deaths, where it was unclear to the police before the forensic autopsy whether or not the death resulted from a criminal act. Our findings suggest that the number of forensic autopsies will continue to increase into the future in Chiba prefecture, and is a trend that is inevitable if we are to prevent criminal death cases from being overlooked. Although referrals for forensic autopsy in Japan are made only when criminal activity is suspected, the original purpose of death investigations is not only to avoid overlooking crimes, but also to flag public health issues. Therefore, together with the police, we need to review the original purpose and conduct more in-depth discussions about when referrals are necessary.

A fatal case of adult small bowel volvulus.

A 56-year-old man was hit by a car while riding a bicycle, immediately brought to the hospital, and treated. Four days after the accident, he reported abdominal pain and vomiting in the night, and he died the next day. A forensic autopsy was performed, and almost of the entire small bowel had gangrenous swelling. The mesentery was twisted 180° with clockwise rotation along the vascular axis, and pre-autopsy computed tomography scan showed a whirl sign.

Age estimation by quantitative features of pubic symphysis using multidetector computed tomography.

Macroscopic assessment of the pubic symphysis is commonly used for age estimation because its surface changes over time. However, postmortem computed tomography (PMCT), a method several forensic medical departments and institutes have begun to adopt, has the potential to simplify the information gathering process from the pelvic bone without requiring soft tissue removal. Some studies have previously evaluated the use of three-dimensional images of the pubic symphysis, but because of variance in the graphics processing among image analysis software packages, certain differences have been observed between these studies. Therefore, in this study, the PMCT findings of 199 subjects of known age and sex were retrospectively reviewed to examine the feasibility of age estimation using planar images of the pubic bones and soft tissue. The coronal and axial sectional images were observed at the center of the symphyseal surface, and the pubic bone length and thickness of the connective tissue of the pubic symphysis were measured at each slice. Our results revealed a significant positive correlation between the length of the pubic bone of the coronal section and age, suggesting that the use of a cutoff value for pubic bone length might be feasible for age estimations. In addition, the thickness of the connective tissue tended to narrow over time. Although the prediction interval range of planar images obtained by PMCT was major and is not usable in practice at this moment, it may still be a useful tool if used in conjunction with other findings obtained by PMCT.

Stature estimation based on radial and ulnar lengths using three-dimensional images from multidetector computed tomography in a Japanese population.

The aim of our study was to evaluate correlations between cadaver stature (CS) and radial and ulnar lengths based on three-dimensional (3D) computed tomography (CT) images, and to develop modern regression equations for estimating CS in a Japanese population. Measurements were performed on 245 Japanese subjects (123 males and 122 females) who underwent postmortem CT between May 2011 and December 2013. A 3D reconstructed image was used for assessment. The linear distances of the left radial (LR) and right radial (RR) lengths were measured as a straight-line distance from the most anteroproximal point of the head to the most distal end of the styloid process. The linear distances of the left ulnar (LU) and right ulnar (RU) lengths were measured as a straight-line distance from the most posteroproximal point of the olecranon to the most distal end of the styloid process. The correlation between CS and each parameter (LR, LU, RR, and RU) was assessed using Pearson product-moment correlation coefficients and regression analysis was performed for stature estimation. There were significant correlations between CS and each parameter regardless of sex, indicating that the radial and ulnar lengths measured on 3D CT images can be predictive of stature estimation. Simple regression equations for stature estimation calculated from LR provided the lowest standard error of estimation (SEE) (all subjects, SEE=4.18 cm; males, SEE=4.09 cm; females, SEE=4.21 cm). In addition, multiple regression equations were more accurate and reliable than the single linear regression equations.

Bilateral middle cerebral artery infarction associated with traumatic common carotid artery dissection: a case report and review of literature.

Traumatic common carotid artery dissection is very rare, and although it is associated with mild symptoms, it can sometimes be fatal. Therefore, careful examination of common carotid artery dissection and additional pathological examination as appropriate are important during the autopsy of traumatic death patients. A 60-year-old previously healthy drunken woman was run over. She had remained unconscious shortly after the accident, and 15 h later, emerging bilateral cerebral infarction was confirmed using brain computed tomography. Despite conservative management, she died 4 days after the injury due to multiple chest traumas and broad cerebral infarction. A medico-legal autopsy was conducted. According to the autopsy results, microscopically identified common carotid artery dissections with thrombus formation were considered the cause of infarction. In the present case, macroscopic common carotid artery lesions were relatively mild, and this made diagnosis difficult. However, the correct diagnosis was achieved by a combined analysis of the antemortem images and autopsy results. Thus, in such cases, a combined comprehensive analysis of autopsy results and antemortem clinical images is important to determine the exact cause of death.

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.

Statistical analysis of biomechanical properties of the adult skull and age-related structural changes by sex in a Japanese forensic sample.

The purpose of this research was to investigate the biomechanical properties of the adult human skull and the structural changes that occur with age in both sexes. The heads of 94 Japanese cadavers (54 male cadavers, 40 female cadavers) autopsied in our department were used in this research. A total of 376 cranial samples, four from each skull, were collected. Sample fracture load was measured by a bending test. A statistically significant negative correlation between the sample fracture load and cadaver age was found. This indicates that the stiffness of cranial bones in Japanese individuals decreases with age, and the risk of skull fracture thus probably increases with age. Prior to the bending test, the sample mass, the sample thickness, the ratio of the sample thickness to cadaver stature (ST/CS), and the sample density were measured and calculated. Significant negative correlations between cadaver age and sample thickness, ST/CS, and the sample density were observed only among the female samples. Computerized tomographic (CT) images of 358 cranial samples were available. The computed tomography value (CT value) of cancellous bone which refers to a quantitative scale for describing radiodensity, cancellous bone thickness and cortical bone thickness were measured and calculated. Significant negative correlation between cadaver age and the CT value or cortical bone thickness was observed only among the female samples. These findings suggest that the skull is substantially affected by decreased bone metabolism resulting from osteoporosis. Therefore, osteoporosis prevention and treatment may increase cranial stiffness and reinforce the skull structure, leading to a decrease in the risk of skull fractures.

A suspected case of coronary periarteritis due to IgG4-related disease as a cause of ischemic heart disease.

IgG4-related disease (IgG4-RD) is a systemic inflammatory disease characterized by marked infiltration of IgG4-positive (+) plasma cells into affected organs, but the concept of this disease has only recently been established. Coronary vasculitis is a rare disease that can cause sudden death, and it has recently been reported that IgG4-RD may be associated with vasculitis, including periarteritis and coronary disease. In this paper we report an autopsy case of sudden death of a man in his thirties, in which coronary periarteritis with features of IgG4-related periarteritis was detected. IgG4-RD was suspected from the presence of the following histopathological features: (1) markedly thickened adventitia and marked infiltration of the adventitia and periarterial fat by lymphocytes and plasma cells; and (2) infiltration of IgG4-positive plasma cells (ratio of IgG4+ cells to IgG4+ cells of >40 %, 50 IgG4+ plasma cells per high-power field) on immunostaining. The etiology and pathophysiology of IgG4-RD and IgG4-related periarteritis are still unclear, and further investigation of these conditions and their association with coronary lesions is needed. Careful consideration should be given to the possible presence of IgG4-RD when forensic pathologists encounter cases of sudden death accompanied by coronary periarteritis.

Effects of the freezing and thawing process on biomechanical properties of the human skull.

The aim of this study was to determine if biomechanical investigations of skull samples are reliable after skulls have been subjected to a freezing and thawing process. The skulls were obtained from 105 Japanese cadavers (66 males, 39 females) of known age that were autopsied in our department between October 2012 and June 2013. We obtained bone specimens from eight sites (four bilaterally symmetrical pairs) of each skull and measured the mass of each specimen. They were then classified into three groups (A, B, C) based on the duration of freezing of the experimental samples. The left-side samples were subjected to frozen storage (experimental group). The corresponding right-side samples were their controls. Bending tests were performed on the controls immediately after they were obtained. The experimental samples were preserved by refrigeration at -20 °C for 1 day (group A), 1 month (group B), or 3 months (group C). Following refrigeration, these samples were placed at 37 °C to thaw for 1 h and then were subjected to bending tests using a three-point-bending apparatus attached to a Handy force gauge. The device recorded the fracture load automatically when the specimen fractured. Statistical analyses revealed that there were no significant differences in sample fracture loads between the frozen preserved/thawed samples and the unfrozen controls for each of the cryopreservation intervals. We eliminated any possible sample mass bias by using controls from the same skull in each case. The results suggest that the freezing/thawing process has little effect on the mechanical properties of human skulls. Thus, frozen storage for up to 3 months is a good method for preserving human skulls.

Diagnosis of drowning by summation of sodium, potassium and chloride ion levels in pleural effusion: differentiating between freshwater and seawater drowning and application to bathtub deaths.

Although electrolyte analysis of pleural effusion at autopsy is useful for the diagnosis of water aspiration (i.e., drowning), the method of comparing each level of sodium (Na(+)), potassium (K(+)), and chloride (Cl(-)) ions does not clearly differentiate between freshwater drowning, seawater drowning, and non-drowning. Therefore, here we introduce the summation of Na(+), K(+), and Cl(-) levels, that is SUM(Na+K+Cl), as a modified diagnostic indicator. In 21 autopsy cases of freshwater drowning, 32 cases of seawater drowning, and 43 non-drowning controls (with pleural effusion), mean SUM(Na+K+Cl) differed significantly between the groups (188.8±33.2, 403.5±107.9, and 239.3±21.7 mEq/L, respectively). We defined a SUM(Na+K+Cl) cut-off value of <195.9 mEq/L as strongly suggestive of freshwater aspiration and that of >282.7 mEq/L as strongly suggestive of seawater aspiration. When these values were applied to the two drowning groups, 15 cases (71%) of freshwater drowning and 29 cases (91%) of seawater drowning were diagnosed correctly. This new approach may be more valid than previous methods in cases found >2 days after death or those with substantial pleural effusion (>100 mL). For an additional 15 bathtub deaths, mean SUM(Na+K+Cl) was 198.8±40.0 mEq/L, and in 14 of these cases (93%) the relationship between cause of death and SUM(Na+K+Cl) could be explained using this method. Forensic pathologists should not depend exclusively on chemical findings and should consider also typical pathological indicators of drowning. This new method may be useful as a supplementary diagnostic tool when used alongside consideration of the pathological findings.

Age estimation based on pulp cavity to tooth volume ratio using postmortem computed tomography images.

Pulp cavity size is known to decrease with age and can therefore serve as an indicator for age estimation. Here, we evaluated whether reconstructed images of multidetector-row computed tomography (MDCT) acquired before forensic autopsy are useful for estimating age at death. Images of 136 mandibular first premolars obtained from bodies of known age at death were analyzed, and the volume of the regions corresponding to pulp cavity and that of the whole tooth were determined using a voxel counting function. The pulp cavity was clearly distinguishable from dental hard tissue on the reconstructed images when using a cutoff value of 1400 Hounsfield units. Regression analysis adjusted for sex showed that estimated age correlated significantly with the pulp cavity to tooth volume ratio (r = 0.76). MDCT is gaining more widespread use in forensic medicine, and analyzing dental images to obtain parameters for age prediction is a practical approach for postmortem identification.