F. Ramsthaler

The problem of aging human remains and living individuals: A review

Forensic anthropology is affected by the unavoidable limits concerning difficulties in standardization of methods and procedures; age estimation is one of the main tasks of forensic anthropology and odontology, both on the dead and the living: literature has shown several methods of age estimation, and although they may be thought of as equivalent, every procedure has its limits, mean error, practical situation and age range where it gives the best results; the lack of standardization and consensus concerning which method can be used, as well as the lack of a practical approach in different cases is the main limit in a correct age estimation process. This review aims at exposing the experience of the authors working in the FASE (Forensic Anthropology Society of Europe) subsection of IALM (International Academy of Legal Medicine) in the field of age estimation both on the dead and the living, at highlighting advantages and limits of each method, and suggesting practical solutions concerning the age estimation process for adults and subadults, dead and living, and pedopornographic material.

Digital forensic osteology: Morphological sexing of skeletal remains using volume-rendered cranial CT scans

Because of the increasing lack of recent bone collections, ethical issues concerning maceration procedures, and progress in radiological imaging techniques, computed tomography (CT) scans offer an alternative to traditional anthropological bone collection. The present study examined volume-rendered cranial CT (CCT) scans from 50 crania to morphologically evaluate sex characteristics. CCT scans were performed and scored by two teams (Teams A and B) of two examiners each (2x50=100 examinations) to evaluate the occurrence and/or absence of morphological traits. Altogether, 60 of 100 crania (31 Team A+29 Team B) crania were determined to be male, and 40 (19 Team A+21 Team B) were determined to be female when using the scoring system adapted from Knussmann. These results imply a sex determination accuracy rate of 96%. Only in one case was recalculation of weighting factors necessary to determine one additional correct classification. As a single parameter, arcus superciliaris evaluation permitted the most accurate sex determination (female, 84.2%; male, 85.5%). No significant difference in accuracy rates was observed between the two sexes (p<0.65, chi(2)=0.39, Fishers exact test). Interobserver bias rates for both teams were very low (kappa=0.83). The present study shows that volume-rendered CCT images are suitable for the collection of data concerning morphologic sex determination of skulls. Thus, this method may be helpful in both actual forensic casework and the systematic reevaluation and improvement of classical anthropological methods and their adaptation to changing populations.

Evaluation of the ossification of the medial clavicular epiphysis with a digital ultrasonic system to determine the age threshold of 21 years

In this study, both medial clavicular epiphyses of 77 men were evaluated by two researchers with a digital ultrasound system. The degree of ossification was classified in four stages according to Schulz et al. (Int J Legal Med 122:55–58, 17). Of the test persons over 21xa0years of age, stage 4 was found bilaterally in 25 (60%), while for five (12%) stage 4 was found on only one side; 12 (28%) further subjects did not show stage 4 on either side, although nine were exactly 21xa0years old. For the subjects under 21xa0years of age, stage 4 was found bilaterally in three cases (8.5%), and in three additional cases stage 4 was found on one side. Particularly, the three cases in which stage 4 was diagnosed bilaterally before completion of the 21st year of age limit the value of the used examinatory technique. For these cases it would be interesting to know if parts of the epiphyseal plate that might have been obstructed from the view of the ultrasound transducer would have been visible with CT.

Accuracy of metric sex analysis of skeletal remains using Fordisc® based on a recent skull collection

It has been generally accepted in skeletal sex determination that the use of metric methods is limited due to the population dependence of the multivariate algorithms. The aim of the study was to verify the applicability of software-based sex estimations outside the reference population group for which discriminant equations have been developed. We examined 98 skulls from recent forensic cases of known age, sex, and Caucasian ancestry from cranium collections in Frankfurt and Mainz (Germany) to determine the accuracy of sex determination using the statistical software solution Fordisc® which derives its database and functions from the US American Forensic Database. In a comparison between metric analysis using Fordisc® and morphological determination of sex, average accuracy for both sexes was 86 vs 94%, respectively, and males were identified more accurately than females. The ratio of the true test result rate to the false test result rate was not statistically different for the two methodological approaches at a significance level of 0.05 but was statistically different at a level of 0.10 (pu2009=u20090.06). Possible explanations for this difference comprise different ancestry, age distribution, and socio-economic status compared to the Fordisc® reference sample. It is likely that a discriminant function analysis on the basis of more similar European reference samples will lead to more valid and reliable sexing results. The use of Fordisc® as a single method for the estimation of sex of recent skeletal remains in Europe cannot be recommended without additional morphological assessment and without a built-in software update based on modern European reference samples.

How reliable are the risk estimates for X-ray examinations in forensic age estimations? A safety update

Possible biological side effects of exposure to X-rays are stochastic effects such as carcinogenesis and genetic alterations. In recent years, a number of new studies have been published about the special cancer risk that children may suffer from diagnostic X-rays. Children and adolescents who constitute many of the probands in forensic age-estimation proceedings are considerably more sensitive to the carcinogenic risks of ionizing radiation than adults. Established doses for X-ray examinations in forensic age estimations vary from less than 0.1xa0μSv (left hand X-ray) up to more than 800xa0μSv (computed tomography). Computed tomography in children, as a relatively high-dose procedure, is of particular interest because the doses involved are near to the lower limit of the doses observed and analyzed in A-bombing survivor studies. From these studies, direct epidemiological data exist concerning the lifetime cancer risk. Since there is no medical indication for forensic age examinations, it should be stressed that only safe methods are generally acceptable. This paper reviews current knowledge on cancer risks associated with diagnostic radiation and aims to help forensic experts, dentists, and pediatricians evaluate the risk from radiation when using X-rays in age-estimation procedures.

Dating skeletal remains with luminol-chemiluminescence. Validity, intra- and interobserver error.

UNLABELLEDnAmongst numerous other morphological, chemical, physical, and histological dating methods, the assessment of the chemiluminescence of weathered organic traces on bone finds by means of the luminol reaction is common practice. Opinion differs on the diagnostic value of this procedure for differentiating between historical and recent skeletonized human remains.nnnDESIGNnChemiluminescence (CL) was tested in randomized, blind experiments on pulverized bone samples with known postmortem intervals from four different periods (1st-3rd century, 1878-1902, 1965-1972, 1995-2003). In addition to determining the sensitivity and specificity of the CL-analysis, likelihood ratios and predictive values were calculated. The degree of interobserver and intraobserver agreement was determined using Kappa statistics.nnnRESULTSnBased on our sample, we found false positive results in approximately 7.5% of all examined historical cases and false negative results in approximately 15% of the recent samples. Altogether, a correct classification of 88.75% (overall classification) was found (sensitivity=0.85, specificity=0.925; likelihood ratio=11.3; odds ratio=69.8). Taking a-priori probabilities into consideration (prevalence for recent=26%), a positive predictive value (PPV) of only 79.9% could be calculated, while the negative predictive value (NPV) lay at 94.6%. The results from subsequent Kappa statistics further illustrated that the quality of the results was, on the whole, observer independent (kappa=0.93; 95% CI=0.84-1.0). Intraobserver bias calculation yielded a value of kappa=0.975 (95% CI=0.92-1.0).nnnCONCLUSIONnThe analysis of CL on dry bones in determining the postmortem interval is not valid as an only method. In other respects, the luminol test is reproducible, repeatable and cost-effective and could help in assessing the postmortem interval (PMI). The results of this study document the potential danger of forensically relevant cases being erroneously sorted out if further examinations do not take place. We would like to emphasize that still only a combination of different methods including the analysis of environmental conditions and the interpretation of the anthropological profile can allow an acceptable estimate of the PMI from skeletonized remains, even if the methodological spectrum is being expanded by different absolute dating methods using radionuclide techniques.

Postmortem interval of skeletal remains through the detection of intraosseal hemin traces. A comparison of UV-fluorescence, luminol, Hexagon-OBTI®, and Combur® tests

With the goal of obtaining additional practically applicable methods for estimating the PMI of skeletal remains, 39 samples of human and 5 samples of domestic animal long bones with known PMI (PMI=1 to approximately 2000 years) were tested with two established methods (UV-fluorescence of a freshly sawn cross-section and the luminol test) and two screening tests (Hexagon-OBTI® test and Combur® test) that were being tried out in this context for the first time. The hypothesis underlying this experiment was the supposition that the PMI-related chemiluminescence of the luminol reaction for bone is based on the presence of persisting hemin from hemoglobin molecules in bone. Our results showed that lack of luminescence and reduced UV-fluorescence were more meaningful results for estimating PMI and excluding forensic relevance than a positive luminol reaction or strong UV-fluorescence, as both of the latter findings revealed the limitations of these methods in this particular context. Particularly for cases showing a positive luminol reaction, the use of additional absolute dating methods may be indicated. Against our expectations, both the Combur® test strips and the Hexagon-OBTI® test, which were both devised to demonstrate blood, delivered negative results for all samples. They are thus not suitable for estimating the PMI of skeletal remains. Future research will be necessary to elucidate whether the negative results obtained for these tests may be due to the poor solubility of potentially present hemoglobin or hemoglobin breakdown products in the Tris buffer used in this experiment.

„Flat-Panel“-Computertomographie in der Rechtsmedizin

ZusammenfassungDie Verwendung der Computertomographie in der Rechtsmedizin etabliert sich zusehends. Aktuelle Multislice-Computertomographen (MSCT) erreichen eine Auflösung von ca. 0,2xa0mm in xy- und 0,6xa0mm in z-Richtung. Noch im vorklinischen Stadium, d.xa0h. nicht für Patienten zugelassen, befinden sich „Flat-Panel“-Computertomographen. Diese verwenden „panels“ zur Strahlendetektion, die ursprünglich für die Angiographie entwickelt wurden. Sie ermöglichen sinnvoll rekonstruierte isotrope Voxelgrößen von (0,05xa0mm)3 – verbunden mit dem Nachteil, dass der maximal scannbare Objektdurchmesser ca. 16xa0cm beträgt. Folglich kann ein menschlicher Körper nicht in toto gescannt werden. Die bildgebende Untersuchung forensisch-osteologischer Proben und im Rahmen von Obduktionen gewonnener Präparate ist jedoch möglich. Für die vorgestellten Untersuchungen stand der eXplore Locus Ultra (eLU) Flat-Panel-CT-Scanner zur Verfügung. Während Obduktionen wurden Herzen, Kehlköpfe sowie Kalotten gescannt und dem Leichnam unmittelbar wieder beigegeben. Außerdem erfolgte die Untersuchung von mazerierten Schädeln. Die Vorteile der höheren Auflösung des eLU zeigten sich v.xa0a. bei der Beurteilung von knöchernen Verletzungen und der Ossifikation der Schädelnähte. Auch Verkalkungen waren gut sichtbar. Dagegen waren bei der Darstellung von Weichteilen deutliche Schwächen festzustellen.AbstractThe use of computed tomography in legal medicine is noticeably becoming mainstream. Current multi-slice computed tomography (MSCT) attains a resolution of 0.2xa0mm in the xy-plane and a resolution of 0.6xa0mm in the z-plane. So called flat panel CT is still in a preclinical phase and has so far not been approved for patient use. Flat Panel CT uses panels for radiation detection that were originally developed for angiography and allows a meaningful reconstruction from isotropic voxel sizes of (0.05xa0mm)3, the disadvantage being that the maximum object diameter that can be scanned is only approximately 16xa0cm. Consequently, the complete human body cannot be scanned, however, imaging examinations of forensic osteology samples and preparations obtained from autopsies are possible. An eXplore Locus Ultra (eLU) flat panel CT scanner was placed at our disposal for the examinations presented in this article. During autopsies, hearts, larynxes, and callottes were scanned and then immediately returned to the corpse. Macerated skulls were also examined. The advantages of the higher resolution of the eLU were especially apparent in the evaluation of bony injuries and the ossification of cranial sutures. Calcification was also easy to visualize, but in contrast, distinct shortcomings were noted in the imaging of soft tissues.

The use of rapid diagnostic test of Procalcitonin serum levels for the postmortem diagnosis of sepsis

Because serum Procalcitonin is reported to be a valid postmortem marker of sepsis, this prospective study was carried out to determine whether the semi-quantitative PCT-Q((R))-Test (B.R.A.H.M.S., Germany) is a reliable indicator of postmortem Procalcitonin (PCT) serum levels, thus enabling a quick tableside diagnosis of sepsis. Postmortem PCT-levels of 70 forensic and 78 clinical-pathological autopsy cases (n=148) were examined using the B.R.A.H.M.S-PCT-Q-Test during autopsy. 27 cases were categorized as the cases of sepsis according to the ACCP/SCCM Consensus Conference criteria. 121 cases were assigned to the non-sepsis group. Among the 148 cases, 18 samples could not be analyzed by the reason of strong hemolysis. Using a cut-off point of 2 ng/ml, 20 cases of sepsis were identified (true positive) whereas 3 cases of sepsis were not detected (false negative). In the non-sepsis group (107 cases) 6 cases showed a positive testing (false positive). When applied within 48 h postmortem, the PCT-Q-Test showed a sensitivity of 86.96% and a specificity of 94.39% (at cut-off 2 ng/ml). Likelihood ratios and positive predictive values proved to be lower in the forensic autopsy group (PPV: 59.3% in forensic case vs. 85.1% in clinicopathological cases; NPV: 98.73% in forensic cases vs. 95.2% in clinicopathological cases). The PPVs using a cut-off point of 10 ng/ml were 100% in both groups independent of sepsis prevalences. The results show, that a high NPV for prevalences ranging from 3% to 30% can be reached using a 2 ng/ml cut-off point, whereas a cut-off of 10 ng/ml ensures a high PPV for the respective prevalences in the absence of exclusion criteria. The study provides strong evidence that the introduction of rapid diagnostic test (RDTs) of postmortem PCT serum levels may be useful in achieving rapid distinction between sepsis and non-sepsis-related causes of death, especially in conjunction with the medical case history and further autopsy results. In addition, the use of RDTs enables clinicians to conduct an evidence-based validation of clinical diagnosis, thus facilitating future clinical decision-making.

Investigations on an isolated skull with gunshot wounds using flat-panel CT

The use of computed tomography (CT) scanners is rapidly becoming established in forensic medicine. Current multislice CT (MSCT) scanners attain a resolution of 0.42xa0mm. An isolated skull with gunshot injuries was examined with a high-resolution eXplore Locus Ultra flat-panel CT (eLU-CT) and MSCT. Structures and minute fissures in the bone interior, which were neither visible macroscopically nor with the MSCT data, could be imaged with the eLU-CT data. In addition, a tiny interior impact defect from a retained missile could be detected by eLU-CT, which clearly aided the reconstruction of the gunshots in this case.