Hitoshi Biwasaka

Analyses of sexual dimorphism of contemporary Japanese using reconstructed three-dimensional CT images – Curvature of the best-fit circle of the greater sciatic notch

We examined various expression methods of sexual dimorphism of the greater sciatic notch (GSN) of the pelvis in contemporary Japanese residents by analyzing the three-dimensional (3D) images reconstructed by multi-slice computed tomography (CT) data, using image-processing and measurement software. Mean error of anthropological measurement values between two skeletonized pelves and their reconstructed 3D-CT images was 1.4%. A spline curve was set along the edge of the GSN of reconstructed pelvic 3D-CT images. Then a best-fit circle for subsets of the spline curve, 5-60mm in length and passing through the deepest point (inflection point) of the GSN, was created, and the radius of the circle (curvature radius) and its ratio to the maximum pelvic height (curvature quotient) were computed. In analysis of images reconstructed from CT data of 180 individuals (male: 91, female: 89), sexes were correctly identified in with 89.4% of specimens, with a spline curve length of 60mm. Because sexing was possible even in deeper regions of the GSN, which are relatively resistant to postmortem damage, the present method may be useful for practical forensic investigation.

Wound age estimation by simultaneous detection of 9 cytokines in human dermal wounds with a multiplex bead-based immunoassay: An estimative method using outsourced examinations

Wound age estimation for human dermal wounds was performed based on quantification of interleukin 1beta (IL 1beta), IL 5, IL 7, IL 12 p70, IL 13, IL 17, granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein 1 (MCP 1), and macrophage inflammatory protein 1beta (MIP 1beta). IL 5, IL 12 p 70, IL 13, and IL 17 increased from the early phase, MCP 1 exclusively in the middle phase, and IL 1beta, G-CSF, and MIP 1beta from the middle phase to the late phase. IL 7 decreased from the early phase. Among the cytokines analyzed in the present study, MCP 1 was the most plentiful cytokine. In addition, an outsourced examination, which could be available to any forensic institute, was performed in two cases for confirmative purposes. Many factors have been proposed as markers for dermal wound age estimation, but the set of cytokines selected for the outsourced examination in the present study wound be useful in daily forensic practice.

Analyses of sexual dimorphism of reconstructed pelvic computed tomography images of contemporary Japanese using curvature of the greater sciatic notch, pubic arch and greater pelvis

Three-dimensional pelvic images were reconstructed from multi-slice CT data of contemporary Japanese (males: 124; females: 104, 25-92 years old), and curvature analysis to examine sexual dimorphism was carried out in the great sciatic notch (GSN), the pubic arch and the greater pelvis in the images. Reconstructed pelvic CT images were visualized fairly well and anatomical landmarks were easily recognizable. When calculating the radii (curvature radii) of the best-fit circles for the spline curve lines set along the edges of the GSNs and of the pubic arches, sexes from these regions were correctly identified in 89.1% (males: 93.8%; females: 83.7%) and 94.7% (males: 97.3%; females: 91.8%) of cases, respectively, by setting an appropriate cut-off value. Furthermore, sexing was possible even in deeper regions of the GSN which are relatively resistant to postmortem damage. Curvature radii of the best-fit spheres of greater pelves showed no significant difference between sexes. However, curvature of the best-fit sphere for the left iliac fossa was significantly larger than that of the right one (p<10(-24)) in males, and the ratios were >1.0 in 88% of all male specimens analyzed. Meanwhile, no significant difference was observed among female samples. Although some left-sided dominancy has been reported in 2-dimensional measurements of the human pelvis, this 3-dimensional laterality in males was much more significant, and is a potential index of sex difference.

Three dimensional surface analyses of pubic symphyseal faces of contemporary Japanese reconstructed with 3D digitized scanner

Three dimensional pubic bone images were analyzed to quantify some age-dependent morphological changes of the symphyseal faces of contemporary Japanese residents. The images were synthesized from 145 bone specimens with 3D measuring device. Phases of Suchey-Brooks system were determined on the 3D pubic symphyseal images without discrepancy from those carried out on the real bones because of the high fidelity. Subsequently, mean curvatures of the pubic symphyseal faces to examine concavo-convex condition of the surfaces were analyzed on the 3D images. Average values of absolute mean curvatures of phase 1 and 2 groups were higher than those of phase 3-6 ones, whereas the values were approximately constant over phase 3 presumably reflecting the inactivation of pubic faces over phase 3. Ratio of the concave areas increased gradually with progressing phase or age classes, although convex areas were predominant in every phase.

Distinct breakpoints in two cases with deletion in the Yp11.2 region in Japanese population

The amelogenin gene on the Y chromosome (AMELY) is a homolog of the X chromosome amelogenin gene (AMELX), and the marker is employed for sexing in forensic casework. Deletion of the sequences in the Yp11.2 region containing the AMELY locus has been found in males from various ethnic populations. Two cases of AMELY null males found in the Japanese population had different Y haplogroups and deletion mapping. Proximal and distal breakpoints of a sample of haplogroup D2* were located in TSPYA and TSPYB arrays, respectively, suggesting that the deletion mechanism was non-allelic homologous recombination (NAHR). On the other hand, a sample of haplogroup O3a3c* had the distal breakpoint in the TSPYB array and the proximal breakpoint at position 7.94 Mb, not in the TSPYA array. The likely deletion mechanism is non-homologous end-joining. High-resolution STS mapping in the TSPYB array showed the distal breakpoints differed according to the haplogroups. The deletion length was estimated as 3.1–3.7 Mb and 1.6–1.7 Mb for the sample of haplogroup D2* and O3a3c*, respectively. These deletion events should have occurred independently.

The Applicability of Holography in Forensic Identification: A Fusion of the Traditional Optical Technique and Digital Technique

In this study, the applicability of holography in the 3-dimensional recording of forensic objects such as skulls and mandibulae, and the accuracy of the reconstructed 3-D images, were examined. The virtual holographic image, which records the 3-dimensional data of the original object, is visually observed on the other side of the holographic plate, and reproduces the 3-dimensional shape of the object well. Another type of holographic image, the real image, is focused on a frosted glass screen, and cross-sectional images of the object can be observed. When measuring the distances between anatomical reference points using an image-processing software, the average deviations in the holographic images as compared to the actual objects were less than 0.1 mm. Therefore, holography could be useful as a 3-dimensional recording method of forensic objects. Two superimposition systems using holographic images were examined. In the 2D-3D system, the transparent virtual holographic image of an object is directly superimposed onto the digitized photograph of the same object on the LCD monitor. On the other hand, in the video system, the holographic image captured by the CCD camera is superimposed onto the digitized photographic image using a personal computer. We found that the discrepancy between the outlines of the superimposed holographic and photographic dental images using the video system was smaller than that using the 2D-3D system. Holography seemed to perform comparably to the computer graphic system; however, a fusion with the digital technique would expand the utility of holography in superimposition.

Application of computerised correction method for optical distortion of two-dimensional facial image in superimposition between three-dimensional and two-dimensional facial images

The applicability of computerised correction of optical distortion to two-dimensional (2D)/three-dimensional (3D) facial image superimposition was investigated. Two-dimensional (2D) facial images of 10 male volunteers were taken with a commercially available closed circuit device (CCD) camera (reference camera) at four areas of the lens field: the centre, top, upper right and right. Correction was made by computer by calculating differences vis-à-vis the co-ordinates of dots on a test chart. Discrepancies in facial outlines between the 3D and 2D images decreased following correction in all lens fields and were below the threshold for true positive. The correction method was also tested using an actual surveillance camera and video recorder installed in a bank. The method was found to be effective for the correction of facial images, especially those taken in the top and right lens fields. Since the total error (observed error) remaining after correction appeared close to the random error (real error), systematic error was thought to be minimised by correction. Therefore, the present method was thought to display high fidelity, and could be useful for supplementary examination of conventional superimposition.

Application of quantitative ethanol detector (QED) test kit to measure ethanol concentration in blood samples.

In this paper, the applicability of the quantitative ethanol detector (QED) test kit for screening of ethanol concentrations in blood samples was investigated. The pretreatment of blood using the sulfosalicylic acid solution and the three-way stopcock followed by membrane filtration gave satisfactory results. The ethanol concentrations in whole blood samples (n=61) determined by QED correlated well with those determined by gas chromatography; the correlation coefficient indicated 0.990. Because a high correlation coefficient (0.928) was also confirmed in trial by investigators, QED test should be highly considered for ethanol screening in forensic praxis.

A quantitative morphological analysis of three-dimensional CT coxal bone images of contemporary Japanese using homologous models for sex and age estimation

Sexual dimorphisms and age-dependent morphological features of the human coxal bone were quantitatively analyzed using homologous models created from three-dimensional (3D) computed tomography images of the pelvis (male: 514 samples, female: 388 samples, age 16-100). Bilateral average coxal images of each sex and age decade were generated separately through principle component analyses (PCA). By measuring average point-to-point distances of 8472 corresponding points (average corresponding point differences [ACPDs]) between each homologous coxal image and the average images, the sex of more than 93% of the samples was correctly assigned. Some principal components (PCs) detected in PCA of the homologous models of the samples correlated fairly well with age and are affected by features of the curvature of the iliac crest, the arcuate line and the greater sciatic notch. Moreover, separate PCA using the average images of each age decade successfully detected the first PCs, which were strongly correlated with age. However, neither multiple regression analysis using PCs related to age nor comparison of ACPDs with the average images of each age decade could produce accurate results for age decade assignment of unknown (blind) samples. Therefore, more detailed analysis of age-dependent morphological features would be necessary for actual age estimation. In addition, some laterality or left and right shape difference of the coxal bone images was also elucidated, and was more significant in females. Analysis of 3D structures using homologous models and PCA appears to be a potential technique to detect subsistent morphological changes of bones.

An autopsy case related to a terrorist attack using a ball-bearing bomb

We encountered an autopsy case related to a terrorist attack using a ball-bearing bomb. The decedent was a 51-year-old male without significant medical histories. During dinner in a restaurant, the perpetrator suddenly exploded a ball-bearing bomb, the blast from which blew the victim off his chair. The victim was found to be unresponsive, and pronounced dead. X-ray photographs taken before autopsy revealed six spherical shadows. Three penetrating wounds in the head, one in the neck and chest, and two in the left upper arm were observed in vivo. Six projectiles recovered from the body were identified as ball-bearings, one of which traveled through the midbrain, diencephalon, and left temporal lobe. Although blast injuries and penetrating wounds are often combined in bomb attack victims, penetrating brain injury would be the cause of death in this case. Lethal injuries to major organs can thus occur even though the destructive force of a ball-bearing bomb is weak. X-ray films were informative for detecting the ball-bearings in this case, suggesting that autopsy imaging is essential in cases of terrorism victims.