Intraindividual incongruences of medially ossifying clavicles in borderline adults as seen from thin-slice CT studies of 2595 male persons

Forensic age estimation at the University Center of Legal Medicine Lausanne-Geneva: a retrospective study over 12 years

With the undeniable increase in asylum requests from unaccompanied alleged minors, age estimation of living individuals has become an essential part of the routine work in European forensic centers. This study aims to review the forensic age estimations performed in our center since 2010, to evaluate the state-of-the-art of this practice in Switzerland with the evolution of the methodology according to upcoming recommendations. Our institute's expert reports performed between 2010 and 2022 were retrospectively analyzed. We gathered the following parameters: demographic data, morphological characteristics, alleged age compared with the assessed minimum age, sexual maturation, dental and bone age. When available, we collected personal and family history, medical history, records of torture-related/self-inflicted injuries, and information about eating habits that might affect skeletal development. Data collection amounted to 656 cases. Forensic age estimations ordered by the Swiss Secretariat for Migration (SEM) represented 76.4% of cases, with 23.6% of them ordered by the Court/Public Prosecutor. Most alleged minors were male (94.5%) and came from Afghanistan (53.4%). Adjunction of CT scans of the sternoclavicular joints was necessary in 86.4% of cases. Only 25.2% of our reports concluded on most probable minority, with 55.6% of definite majors; in 19.2% of our cases, minority could not be excluded. This study aspires to further broaden our expertise regarding forensic age estimations. Given the increasing migratory flows, we can expect a notable increase in the frequency of these requests. Consequently, this study aims to promote a multidisciplinary approach and the international standardization of the methodology of these estimations.

Forensic Diagnostics of the Skeletal Age in the Living - Backgrounds and Methodology

BACKGROUND

 The expert opinions on forensic age diagnostics requested by state institutions are used to show the exceeding of legally relevant age thresholds, especially the completed 18th year of life. According to the recommendations of the Study Group on Forensic Age Diagnostics (AGFAD), this requires - among other things - a determination of skeletal age.

METHOD

 Considering recent scientific knowledge, the current conditions and established skeletal age diagnostics methods are presented. Additionally, this review article sheds light on the influence of ethnicity and socioeconomic status, questions regarding indication, as well as alternative and future developments.

RESULTS AND CONCLUSION

 In forensic age diagnostics, particularly hand radiography and thin-slice CT of the medial clavicular epiphysis are relevant for determining skeletal age. The Atlas method of Greulich and Pyle (1959) and the clavicular stages by Schmeling et al. (2004) and Kellinghaus et al. (2010) are primarily used for this. This spectrum of methods, which is based on a very solid database, might be supplemented by MRI studies of the knee joint in the near future.

KEY POINTS

  · Determining skeletal age is an essential part of forensic age diagnostics commissioned by state authorities and courts.. · Hand radiography and CT of the medial clavicular epiphysis form the core of the spectrum of methods recommended by the Study Group of Forensic Age Diagnostics (AGFAD).. · Since the radiological studies required for forensic age diagnostics are not medically indicated, it must be ensured that the legal basis is specifically named in each case when commissioning expert opinions.. · MRI studies of the knee joint might increase the spectrum of methods in the near future..

CITATION FORMAT

· Wittschieber D, Hahnemann ML, Mentzel H. Forensic Diagnostics of the Skeletal Age in the Living - Backgrounds and Methodology. Fortschr Röntgenstr 2024; 196: 254 - 261.

Standards of practice in forensic age estimation with CT of the medial clavicular epiphysis-a systematic review

The AGFAD (Arbeitsgemeinschaft für Forensische Alterdiagnostik, Study Group on Forensic Age Diagnostics) has published several recommendations regarding both technical aspects of computed tomography (CT) of the medial clavicular epiphysis (MCE) and the process of reading and interpreting the CT images for forensic age estimations (FAE). There are, however, no published recommendations regarding CT scan protocols and no dose reference values for CT of the MCE. The objective of this analysis was to assess adherence to AGFAD recommendations among practitioners of FAE and analyse reported dose-relevant CT scan parameters with the objective of helping to establish evidence-based dose reference values for FAE. A systematic literature search was conducted in PubMed and in Google Scholar with specific MeSH terms to identify original research articles on FAE with CT of the MCE from 1997 to 2022. A total of 48 studies were included. Adherence to AGFAD recommendations among practitioners of FAE is high regarding the use of Schmeling main stages (93%), bone window (79%), ≤ 1 mm CT slices (67%), axial/coronal CT images (65%), and Kellinghaus sub-stages (59%). The reporting of CT technique and CT dose-relevant scan parameters is heterogeneous and often incomplete in the current literature. Considering the success achieved by the AGFAD in creating standards of practice of FAE in living subjects, there is potential for the AGFAD to establish standards for radiation protection in FAE as well.

CT of the medial clavicular epiphysis for forensic age estimation: hands up?

Purpose

The aim of this study was to assess the impact of arm position in computed tomography (CT) of the clavicle performed for forensic age estimation on clavicular position, image noise, and radiation dose.

Methods and materials

Forty-seven CT scans of the medial clavicular epiphysis performed for forensic age estimation were conducted with either hands and arms held upwards (CT_HU, 28 persons) or positioned at the body (CT_HD, 19 persons). Presets were identical for both positions (70 mAs/140 kVp; Brilliance iCT, Philips). Each CT scan was reconstructed with an iterative algorithm (i-Dose 4) and evaluated at the middle of the sternoclavicular joint. Clavicular angle was measured on a.p. topograms in relation to a horizontal line. Quantitative image noise was measured in air at the level of medial clavicular epiphysis. Effective dose and scan length were recorded.

Results

Hands-up position compared with hands-down position resulted in a lower lateral body diameter (CT_HU 41.1 ± 3.6 cm vs. CT_HD 44.6 ± 3.1 cm; P = 0.03), a reduced quantitative image noise (CT_HU: 39.5 ± 9.2; CT_HD: 46.2 ± 8.3; P = 0.02), and lower CTDI_vol (5.1 ± 1.4 mGy vs. 6.7 ± 1.8 mGy; P = 0.001). Scan length was longer in patients examined with hands up (HU: 8.5 ± 3.4 cm; HD: 6.2 ± 2.1 cm; P = 0.006). Mean effective dose for CT_HU was 0.79 ± 0.32 mSv compared with 0.95 ± 0.38 mSv in CT_HD (P = 0.12). Clavicular angle was 17° ± 6° in patients with hands down and 32° ± 7° in patients with hands up (P < 0.001).

Conclusion

By elevated arm positioning, the image quality of clavicular CT scans can be improved while maintaining radiation dose compared with hands down. Clavicular position differs according to the hand position. Thus, positioning patients with elevated hands is advisable for forensic clavicular CT examinations, but multiplanar CT reconstructions should be adjusted to clavicular position and scan length should be reduced to a minimum.

Die Aussagekraft sozialpädagogischer Altersschätzungen im Vergleich zur forensischen Altersdiagnostik

In der vorliegenden Studie sollte die Aussagekraft sozialpädagogischer Altersschätzungen im Vergleich zu forensischen Altersbegutachtungen, die entsprechend den Empfehlungen der Arbeitsgemeinschaft für Forensische Altersdiagnostik durchgeführt worden waren, analysiert werden. Hierfür wurden 47 Fälle ausgewertet, bei denen sowohl sozialpädagogische Altersschätzungen von in Jugendhilfeeinrichtungen betreuten unbegleiteten minderjährigen Flüchtlingen als auch forensische Altersgutachten zur Verfügung standen. In 44 Fällen, in denen die Einrichtungen von Minderjährigkeit ausgingen, bescheinigten die forensischen Altersgutachten in 12 Fällen zweifelsfreie Volljährigkeit und in 24 weiteren Fällen wahrscheinliche Volljährigkeit. In 2 Fällen, in denen die Einrichtungen die Minderjährigkeit anzweifelten, wurden im Ergebnis der forensischen Altersbegutachtung in dem einen Fall zweifelsfreie Volljährigkeit und in dem anderen Fall wahrscheinliche Volljährigkeit festgestellt. In einem Fall, in dem die Einrichtung von Volljährigkeit ausging, wurde auf der Grundlage der forensischen Altersbegutachtung wahrscheinliche Volljährigkeit mit noch möglicher Minderjährigkeit attestiert. Objektivierbare psychosoziale Kriterien, mit denen Volljährigkeit zweifelsfrei festgestellt werden kann, ließen sich nicht erkennen. Es ist davon auszugehen, dass der Anteil falsch-positiver Minderjährigkeitsfeststellungen bei sozialpädagogischen Altersschätzungen deutlich höher als bei forensischen Altersbegutachtungen ist. Ebenso scheint ein relevantes Risiko falsch-positiver Volljährigkeitsfeststellungen bei sozialpädagogischen Altersschätzungen zu bestehen. Es wurde geschlussfolgert, dass sozialpädagogische Altersschätzungen keine überzeugende Alternative zu forensischen Altersbegutachtungen darstellen.

Juristische Aspekte der forensischen Altersdiagnostik auf der Grundlage des § 42f SGB VIII

Seit Inkrafttreten des § 42f SGB VIII am 01.11.2015 ist das Verfahren zur Altersfeststellung von unbegleiteten und fraglich minderjährigen Ausländern durch Jugendämter in Deutschland gesetzlich geregelt. Hiernach hat das Jugendamt die Minderjährigkeit zunächst durch Einsichtnahme in die Ausweispapiere des jungen Menschen zu prüfen. Fehlen gültige Ausweispapiere, oder sind die in ihnen enthaltenen Geburtsdaten zweifelhaft, haben Jugendamtsmitarbeiter die Minderjährigkeit mittels einer qualifizierten Inaugenscheinnahme zu beurteilen. Lässt sich auch dadurch eine Minderjährigkeit nicht zweifelsfrei ausschließen, hat das Jugendamt eine ärztliche Untersuchung zur Altersfeststellung zu veranlassen. Eine Analyse der einschlägigen Rechtsprechung sowie der juristischen Fachliteratur ergab, dass Röntgenuntersuchungen zur forensischen Altersdiagnostik auf der Grundlage des § 42f SGB VIII nicht nur zulässig sind, sondern diese auch ausdrücklich eingefordert werden. Die Rechtsprechung erkennt zudem die medizinischen Untersuchungen nach den Empfehlungen der Arbeitsgemeinschaft für Forensische Altersdiagnostik (AGFAD) zur Altersdiagnostik unbegleiteter minderjähriger Ausländer als rechtlich zulässige, valide und zumutbare Methode an. Der von der Zentralen Ethikkommission (ZEKO) bei der Bundesärztekammer vertretenen Auffassung, dass die von der AGFAD empfohlenen Methoden nicht geeignet seien, Volljährigkeit hinreichend zuverlässig nachzuweisen, wird von der Rechtsprechung nicht gefolgt. Vielmehr wird darauf verwiesen, dass durch die Anwendung des Mindestalterkonzepts die von der ZEKO geäußerten Bedenken hinsichtlich der Schwankungsbreiten medizinischer Untersuchungen ausgeräumt werden.

Age-Related Trends in the Trabecular Micro-Architecture of the Medial Clavicle: Is It of Use in Forensic Science?

The mechanical and structural properties of bone are known to change significantly with age. Within forensic and archaeological investigations, the medial end of the clavicle is typically used for estimating the age-at-death of an unknown individual. Although, this region of the skeleton is of interest to forensic and clinical domains, alterations beyond the macro-scale have not been fully explored. For this study, non-destructive micro-computed tomography (μ-CT) was employed to characterize structural alterations to the cancellous bone of the medial clavicle. Fresh human cadaveric specimens (12-59 years) obtained at autopsy were utilized for this study, and were scanned with a voxel size of ~83 μm. Morphometric properties were quantified and indicated that the bone volume, connectivity density, mineral density, and number of trabeculae decreased with age, while the spacing between the trabeculae increased with age. In contrast to other sub-regions of the skeleton, trabecular thickness, and degree of anisotropy did not correlate with age. Collectively, this could suggest that the network is becoming increasingly perforated with age rather than exhibiting trabecular thinning. These results are used in the context of deriving a potential protocol for forensic investigations by using this particular and largely unexplored region of the skeleton, and provide inspiration for future experiments concerning micro-architectural and small scale changes in other regions of the human skeleton.

Forensic age assessment of living adolescents and young adults at the Institute of Legal Medicine, Münster, from 2009 to 2018

Due to high migration inflows to Europe, forensic age assessment of living persons has clearly gained importance. If there is a legal justification for X-ray examinations without a medical indication, the Study Group on Forensic Age Diagnostics (AGFAD) recommends the combination of a physical examination with anamnesis, an X-ray examination of the hand and a dental examination with evaluation of an orthopantomogram for age assessments of adolescents and young adults. If the development of the hand skeleton has been completed, an additional CT examination of the clavicles is to be performed. To demonstrate the outcome of forensic age assessments according to AGFAD recommendations with regard to migrants of doubtful minority declaration, this study analyzes the expert reports carried out at the Institute of Legal Medicine, Münster, from 2009 to 2018. A total of 597 age assessments were performed during the study period. A total of 227 age assessments were issued on behalf of youth welfare offices in the legal area of social law, 282 in family law proceedings, 76 in criminal proceedings, and 12 age assessments in immigration law proceedings. In 211 out of 597 cases, the stated age was compatible with the findings of the age assessment. In the remaining 386 cases, the average difference between the stated age and the minimum age was 1.9 years. The average difference between stated age and most probable age was 5.1 years. Of the 521 age assessments carried out outside criminal proceedings, 197 unaccompanied minors with questionable age minority (37.8%) have reached the age of majority beyond doubt. A total of 388 unaccompanied minors (74.5%) have most probably reached the age of majority. Forensic age assessments with the AGFAD methodology make an important contribution to legal certainty, the welfare of the child, and the fair distribution of resources.

Comparison of different iterative CT reconstruction techniques and filtered back projection for assessment of the medial clavicular epiphysis in forensic age estimation

PURPOSE

To assess the impact of iterative reconstruction and filtered back projection (FBP) on image quality in computed tomography (CT)-based forensic age estimation of the medial clavicular epiphysis.

METHODS AND MATERIALS

CT of the clavicle was performed in 19 patients due to forensic reasons (70 mAs/140 kVp). Raw data were reconstructed with FBP and with an iterative algorithm at level 4 and 6. Clavicular ossification stage was determined by two radiologists in consensus, firstly on FBP reconstructed images and secondly after reviewing all reconstructions including iDose 4 and 6. In addition, the 3 reconstructions were compared regarding artefacts and delineation of the meta-/epiphyseal interface. Quantitative image noise was measured.

RESULTS

Quantitative noise was lower in iDose 6 reconstructed images than in FBP (P < 0.042), but not significantly lower between iDose 4 and FBP (P = 0.127). Side by side comparison revealed lesser qualitative image noise on both iDose reconstructed images than for FBP. The meta-/epiphyseal interface delineation was rated better on both iDose levels than with FBP. In 3 of 19 patients, the clavicular ossification stage was reclassified after iterative reconstructions had been additionally reviewed.

CONCLUSION

Using iterative CT reconstruction algorithms, a reduction of image noise and an enhancement of image quality regarding the meta-/epiphyseal clavicular interface can be achieved. The study highlights the importance of image standardization as variation of reconstruction technique has impact on forensic age estimation.

Staging Clavicular Development on MRI: Pitfalls and Suggestions for Age Estimation

BACKGROUND

MRI of the clavicle's sternal end has been studied for age estimation. Several pitfalls have been noted, but how they affect age estimation performance remains unclear.

PURPOSE/HYPOTHESIS

To further study these pitfalls and to make suggestions for a proper use of clavicle MRI for forensic age estimation. Our hypotheses were that age estimation would benefit from 1) discarding stages 1 and 4/5; 2) including advanced substages 3aa, 3ab, and 3ac; 3) taking both clavicles into account; and 4) excluding morphological variants.

STUDY TYPE

Prospective cross-sectional.

POPULATION

Healthy Caucasian volunteers between 11 and 30 years old (524; 277 females, 247 males).

FIELD STRENGTH/SEQUENCE

3T, T₁ -weighted gradient echo volumetric interpolated breath-hold examination (VIBE) MR-sequence.

ASSESSMENT

Four observers applied the most elaborate staging technique for long bone development that has been described in the current literature (including stages, substages, and advanced substages). One of the observers repeated a random selection of the assessments in 110 participants after a 2-week interval. Furthermore, all observers documented morphological variants.

STATISTICAL TESTS

Weighted kappa quantified reproducibility of staging. Bayes' rule was applied for age estimation with a continuation ratio model for the distribution of the stages. According to the hypotheses, different models were tested. Mean absolute error (MAE) differences between models were compared, as were MAEs between cases with and without morphological variants.

RESULTS

Weighted kappa equaled 0.82 for intraobserver and ranged between 0.60 and 0.64 for interobserver agreement. Stages 1 and 4/5 were allocated interchangeably in 4.3% (54/1258). Age increased steadily in advanced substages of stage 3, but improvement in age estimation was not significant (right P = 0.596; left P = 0.313). The model that included both clavicles and discarded stages 1 and 4/5 yielded an MAE of 1.97 years, a root mean squared error of 2.60 years, and 69% correctly classified minors. Morphological variants rendered significantly higher MAEs (right 3.84 years, P = 0.015; left 2.93 years, P = 0.022).

DATA CONCLUSION

Our results confirmed hypotheses 3) and 4), while hypotheses 1) and 2) remain to be investigated in larger studies.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:377-388.

Anatomic shape variants of extremitas sternalis claviculae as collected from sternoclavicular thin-slice CT-studies of 2820 male borderline-adults

Within medical age assessment practice, the indicator "medial clavicular ossification" constitutes crucial evidence capable of excluding age minority "beyond reasonable doubt" concerning age-disputed individuals doubtfully claiming children's rights during legal procedures. Yet, one of its characteristics affects the morphological variability including a fair amount of downright peculiar appearances. As a result, inexperienced examiners are tempted to classify actually not-assessable formations according to the two established developmental typologies of Schmeling et al. and Kellinghaus et al. being at the same time the most frequent systemic error of age-related clavicular taxation. Since a respective overview appears missing, the study extracts not-assessable shape variants of the medial collar bone from a large sample of 2820 male borderline-adults as seen from thin-slice, sternoclavicular computed tomography. The two already highlighted configurations "more than one, medial, secondary ossification centres" and "medial metaphyseal concavity" are found as the most commonly encountered features impeding reliable delineation of staging criteria. In accordance with previous literature, it is emphasized that "qualified" rating of extremitas sternalis claviculae within age assessment practice presupposes "knowledge about the diversity of [its] anatomic shape variants."

Technical note: utilization of 3D-rendering for CT evaluation of extremitas sternalis claviculae within medical age assessment practice

According to the acknowledged recommendations of the multidisciplinary "Study Group on Forensic Age Diagnostics," the indicator "medial clavicular ossification" carries the potential of delivering decisive evidence to proof age majority "beyond reasonable doubt" regarding age-disputed individuals within legal procedures. Yet, sternoclavicular thin-slice computed tomography, representing its preferred imaging modality, not rarely exhibits peculiar morphologies of the site, sometimes difficult to understand from the usually obtained, axial sections together with coronal reformations. Because of that, we utilized 3D-rendering of acquired CT data in 224 cases with the purpose to gain additional visualization of certain questionable appearances. Concerning reliable classification of medial clavicular ossification in line with the typologies of Schmeling et al. and Kellinghaus et al., it is concluded that such means of illustration contribute to recognition of polygonal or irregular, epiphyseal formations including the not-assessable shape variant "multiple, medial, secondary ossification centres" and of calcification of the articular capsule.