Journal of Forensic Radiology and Imaging最新文献

Introduction

Stature estimation of human skeletal remains is important in medico-legal and forensic anthropology to personal identification. Several investigations have been carried out to estimating the height using the long bones. This study aimed was prediction the height of Iranian people based on the maximum length of femur and tibia by application of X-Ray method.

Methods

This cross-sectional study was conducted in the radiology department of Baqiyatallah Hospital of Tehran, Iran between 2017 and 2018. The number of 166 adult women and men were investigated during the study period. Maximum lengths of the tibia and femur bones were measured on the X-Ray images. In the following, the data were analyzed by SPSS (ver. 22).

Results

The results showed that there was a correlation between the stature and both of the femur and tibia lengths in the men and women (P-value <0.001). However, the highest values of correlation coefficient (R) were detected between the stature and lengths of the men's tibia (R = 0.838) and femur (R = 0.815) and lowest values were identified in the tibia (R = 0.467) and femur(R = 0.431) lengths of the women, respectively. The lowest value for standard error of the estimation (SEE) and the highest value for the coefficient of determination (R²) were observed in multiple regression equation derived from the lengths of the men's femur and tibia (R²=0.736 and SEE=5.64).

Conclusion

Data confirmed that lengths of the tibia and femur of the men yield the best results in terms of the accuracy of the stature estimation in Iranian population.

To investigate effects of obstructive asphyxia on the postmortem computed tomography (PMCT) appearance of lungs, we matched 24 cases of obstructive asphyxia with age-sex matched controls. The initial qualitative impression was that obstructive asphyxia typically appeared to correlate with absence or reduced postmortem hypostasis as well as increased pulmonary radiotranslucency. Categories initially included within obstructive asphyxia were fatal aspiration of gastric contents into lungs, fatally blocked trachea or bronchi due to foreign body, fatal ligature strangulation, fatal manual strangulation and smothering. Method: We manually placed density profile vectors, with start at positionally dependent locations of each lung to derive PMCT densities for multivariate statistics. As fatal gastric content aspiration cases did not significantly differ from the controls, they were re-grouped into the control group for further testing. Results: Quantitatively, the obstructive asphyxia case group featured reduced or absent postmortem hypostasis in the lungs and an overall lower density. Linear multivariate statistics (general linear models, linear discriminant analysis) performed relatively poorly, whereas ”shallow” neural networks yielded significantly better discrimination. With disjunct training and test sets, neural networks achieved correct recognition rates (CRR) of obstructive asphyxia cases of over 95%. Conclusions: Within a more narrowly defined collective of obstructive asphyxia, pulmonary PMCT data appears to contain sufficient information to justify its use in a screening process. This questions the value of an exclusively death scene focused decision making for further investigations and may justify a wider use of PMCT. Conversely, obstructive asphyxia remains difficult to diagnose conclusively based on PMCT alone, so a full autopsy including toxicological analysis are recommended in such cases.

Introduction

Osteometric data may be obtained using digital imaging techniques, such as post-mortem computed tomography (PMCT) and digital radiography, non-invasively and without ethical objection. Osteometric data from PMCT is known to be as accurate as taking direct measurements. Digital radiography is more accessible and affordable than PMCT but is limited due to the magnification of its subjects.

Objectives

To investigate the viability of implementing digital radiographic techniques for measurement of long bones, and to establish whether magnification can be accurately corrected for.

Materials and Methods

Twenty hind pig (Sus scrofa) legs were imaged using computed radiography (CR) and PMCT, and osteometric data obtained from the digital images and 3D CT volume reconstructions. Direct measurements were taken following maceration. A calibration object was imaged using CR, to provide magnification correction factors.

Results

Accuracy was determined by mean absolute error (AE), giving values of 3.3 ± 2.5 mm for PMCT (MPR), 2.4 ± 1.3 mm for PMCT (3D), 11.1 ± 7.4 mm for CR (PA), and 18.3 ± 14.5 mm for CR (LAT). PMCT data was more accurate than CR data. Through applying correction for magnification, CR data became closer to the direct measurement data, and stature estimation was substantially altered.

Conclusion

Magnification in computed radiography affects osteometric data and resulting stature estimations. Applying correction factors may be a viable option for improving accuracy. For digital radiography to be used reliably in forensic anthropology, further empirical research is needed to validate a magnification correction method.

Trepanation, or the removal of a bony piece from the cranial vault, has been widely investigated by both paleopathologists and medical historians. The aim of this report is to employ a paleoradiological approach to complement a macroscopic inspection of the lesions present in a historic case of trepanation from Sicily, to obtain a better understanding of the consequences of the trauma the subject sustained during life, as well as create a permanent, digital record of this unique osteo-archaeological finding for future research.

Rapidly evolving three-dimensional imaging techniques can be effectively employed in forensic sciences to overcome the limitations of two-dimensional imaging modalities. The aim of the present study was to find a threshold value of 18 years age among Malays to differentiate juvenile verses adults based on three-dimensional image analysis of developing mandibular third molars apices. The study also investigated the correlation between chronological age and the surface area of developing mandibular third molars apices. Malay specific regression equation for age estimation was derived. Seventy three mandibular molars were selected from 73 CBCT images belonging to 37 male and 36 female, ranging in age from 15 to 23 years. Mimics and 3-Matics software were employed to generate 3D image models and quantification of surface area analysis of developing mandibular third molars. The results indicated a strong inverse correlation (r = 0.918, SE = 1.025) between chronological age and the predictor variables. The R-Square (R2) value showed that 84.2% of the variation in age can be explained by surface area of the apices, and status of the root development (open/closed apices). Post hoc analysis indicated that the mean value of apex surface area of 18 years age group was significantly different from the mean values of 15, 16, 17, 22 and 23 years age groups. The results indicated that (based on the 95% confidence interval) if the apex surface area is below 9.25 mm², then it is more likely that the Malay person is 18 years of age or above, irrespective of gender.

Craniometric data from computed tomography (CT) head scans of 287 living Americans of three descent groups (African, Asian, European) and both sexes were analyzed for measurement precision. Classification accuracy was estimated by a leave-one-out cross validation, and group means were compared to the Forensic Data Bank (FDB). Landmarks were placed on 3D surface models of the skulls to approximate traditional cranial measurements utilized in sex and ancestry estimations. From repeat measurements by one observer on a subset of skulls (n = 14) reflecting 14 different CT protocols, the least precise landmark was euryon (SD ≤ 4.09 mm) and the least precise distances according to the coefficient of reliability (< 0.95) were orbital breadth, nasal height, and frontal and parietal chords. CT group means were generally larger than FDB means. However, successful classifications of FDB group means into CT groups and vice versa (except for Asians) for both sex and ancestry suggest that cranial measurements taken from clinical CT scans from living individuals are comparable to traditional cranial measurements from individuals in osteological databases. Certain cranial measurements need further examination to determine how best to collect data from CT scans in a way that is most compatible with existing dry skull measurements.

Background A witness reported to the police that a common wood pigeon (columba palumbus) lifelessly had dropped on her balcony immediately after a shot was heard. The dead animal at first appeared to exhibit just a single neck injury. An initial X-ray by the forensic scientist remained unspectacular. Thus it was referred to our unit.

Case / methods The pigeon underwent post mortem computed tomography (PMCT) scanning. The bird was first examined and documented as it was. To examine the skin, the feathers were plucked. Then, a partial autopsy was performed (the skull was not opened).

Results The animal did not show a leg ring. The injury constellation identified a wound track by a single bullet, not typical for an air gun or for shotgun pellets. PMCT showed a multitude of CT-dense round small objects in the pigeon’s craw. Feather damage was consistent with a sitting (not flying) position of the wings. An oblique single wound track was identified from the left leg to the right anterolateral throat region, right through the craw where the exit wound imposed as widely gaping crater-like wound of the throat. The skeletal muscles and organs appeared to be pale. The ascendent aorta had been severed.

Conclusions Conclusive results such as in an assumedly shot animal greatly benefit from a step wise approach. The PMCT results enhance the autopsy findings.

Background

Foramen magnum (FM) attains an increasing interest regarding sex identification among different populations. Computed tomography (CT) is considered a reliable modality for FM examination for forensic purposes.

Aim of the study

The current study is aiming to investigate FM measurements and shape as a forensic tool for sex identification in a sample of Egyptian population using CT imaging technology.

Subjects and Methods

The study included cranial CT images of 200 adult Egyptian individuals (100 males, 100 females) using 320-row multi-detector CT scanner. Sagittal and transverse diameters, index, circumference and area of FM were obtained. FM area was measured automatically and also calculated according to Radinsky's and Teixeria's formulae. FM morphology was also reported.

Results

All FM measurements except FM index were significantly higher in males compared to females. There was no statistical correlation between FM measurements and age. The best overall sex prediction was reported for FM circumference and area measured automatically (67% each), followed by FM area calculated by Radinsky's and Teixeria's formulae (65.5% and 65% respectively), then FM transverse and sagittal diameters (63.5% and 60% respectively). The prediction was raised to 69% when FM circumference, area measured automatically and transverse diameter were combined. Hexagonal and irregular shapes were the most commonly reported shapes in males and females respectively with no statistical difference regarding shape distribution between males and females.

Conclusions

FM measurements are valid sex discriminators in the present Egyptian sample.