N. Telmon

Age assessment by magnetic resonance imaging of the knee: A preliminary study

The authors developed an original magnetic resonance imaging (MRI) staging system for epiphyseal fusion of growth plate maturation of the knee and evaluated its reliability and validity for age assessment of living individuals. A total of 290 MRI scans of the knee were reviewed retrospectively in patients aged from 10 to 30 years old (138 males, 152 females). Five original MRI stages were defined to assess the degree of maturation of the distal femoral and proximal tibial epiphyses. Intra-observer variability was excellent and inter-observer variability was good, demonstrating the reliability and the validity of this original MRI staging system. In both sexes, the changes of growth plates (proximal tibial or distal femoral) were associated with age (p<0.001). Our results agreed with classic data on skeletal maturation of the knee, with globally earlier maturation in females than in males, and also earlier maturation of the proximal tibial epiphysis than of the distal femoral epiphysis. MRI of the knee is an efficient non-invasive method of age assessment, without the disadvantage of X-ray exposure. Further studies with larger groups are needed to support our results.

Multislice Computed Tomography of the First Rib: A Useful Technique for Bone Age Assessment

Abstract:  Macroscopic study of the first rib has been described by Kunos et al. as an efficient method of age estimation. We retrospectively reviewed a test sample of 160 first right ribs obtained from multislice computed tomography (MSCT) clinical investigations of living individuals aged 15–30 years old. Based on the descriptions of Kunos et al., we analyzed the morphological appearance of the sternal end of the first rib on two‐ and three‐dimensional MSCT reconstructions and defined changes in appearance in stages (from 2 to 5). We also studied the calcification and ossification of the costal cartilage as an independent feature. By statistical analysis (ANOVA), we determined for each gender the correlation between the estimated stage of the costal face, the appearance of the costal cartilage, and the documented age of the subjects. We demonstrated that MSCT of the first rib appears to be an efficient noninvasive modality for bone age estimation.

Contribution of distal femur MRI to the determination of the 18-year limit in forensic age estimation.

Dear Editors: We have read with great attention the article “Forensic age estimation in living individuals using 3.0 T MRI of the distal femur” written by Krämer et al. [1]. In this letter, we would like to comment on the contribution of distal femur MRI to determine whether a male is aged 18 years or more. For the paper, Krämer et al. conducted a retrospective study on 3.0 TMR scans of the distal femurs of 290 individuals (166 males and 124 females). The evaluation was based on an analysis of T1-weighted turbo spin-echo (T1-TSE) sequences in sagittal orientation. The authors found that the inferior age limit of stage 4, which was defined as follows: “The epiphyseal cartilage is fully ossified, and the epiphyseal scar is visible,” was 18.3 years in males. They stated that stage 4 did not occur in males before the 18th birthday. This is a crucial finding because in forensic age estimation, the search for the “perfect” indicator regarding the 18-year age limit, i.e., the one that would positively allow an expert to distinguish between minors and majors, is always topical. We decided to verify this result with a simple study. We retrospectively reviewed MR scans of the distal femur obtained in the picture archiving and communication system (McKesson Medical Imaging Group, Richmond, BC, Canada) of the radiology department of Tours, France. We selected only males aged between 14 and 20 years over a 5year period (2009–2013). As usual in this kind of study, subjects were excluded if they had any pathology of the knee (tumor, trauma, infection, or surgical fixation), hormonal disturbance, or general pathology. The socioeconomic status was not taken into account because we had no access to this data. The examinations were performed with a 1.5-T whole-body scanner (Intera, Philips Medical Systems, Amsterdam, The Netherlands). We used a T1-TSE sequence in sagittal orientation. Images were anonymized by deleting the patient’s names and ages, and two observers (PSM and CR) evaluated the images separately and with only one criterion: whether the metaphyseal-epiphyseal junction was totally fused on all images or not. The first observer (PSM) also reviewed each MR scan after 2 weeks. Statistical analysis was performed by R-2.15 [2]. Intraand interobserver variabilities were calculated using Cohen’s nonparametric kappa test [3]. We included 214 patients. Cohen’s kappa test between the two observers was 0.86. Intraobserver variability was also 0.86. All patients younger than 18 years old were evaluated as incompletely fused. Full ossification first occurred at the age of 18.1 years. Table 1 shows the distribution of the sample by age and the number of individuals with a full ossification of the distal femur for each age. This study confirms the results of Krämer et al. [1] on a different sample. It strengthens their statement that if a male has a completely fused distal femur on all MR images of a T1TSE sequence in sagittal orientation, he is at least 18 years old. If the union between the metaphysis and the epiphysis is not complete, no conclusion can be made with regard to the 18year age limit. One major difference between our sample and P. Saint-Martin : C. Rérolle : F. Dedouit :N. Telmon Laboratoire d’Anthropologie Moléculaire et Imagerie de Synthèse (AMIS), UMR 5288, CNRS, 37 allées Jules Guesde, 31073 Toulouse Cedex, France

Is a CT-scan of the medial clavicle epiphysis a good exam to attest to the 18-year threshold in forensic age estimation?

Computed tomography (CT) scan of the medial clavicular epiphysis is one of the methods recommended by the Study Group on Forensic Age Diagnostics to estimate the age of living individuals. The aim of our study was to assess the relationship between the skeletal maturation of the sternal end of the clavicle and the chronological age in a sample of French individuals, using a nine-stage classification. We retrospectively reviewed 319 chest CT-scans of individuals aged 15-30 years old (252 males, 67 females). Among males and females, all individuals with a complete fusion, or an ongoing fusion of more than one third of the total surface of the metaphysis were at least 18 years old. Our results were consistent with data in the literature indicating that individuals with a complete fused clavicle were at least 18 years old. Similar studies with the same methods allow for creating a database of samples from different countries to confirm the validity of this method and its excellent results in forensic age estimation of living individuals.

Old hearts for modern investigations: CT and MR for archaeological human hearts remains

INTRODUCTION Among 800 burials dated between the 15th and 18th centuries and found in the center of Rennes (Brittany, France), a collection of five heart-shaped lead urns was discovered. This material was studied using classical methods (external study, autopsy and histology), and also modern imaging like computed tomography (CT), magnetic resonance (MR) before and after coronary opacification. The aim of this manuscript is to describe different steps of ancient soft tissues study, especially using imaging techniques. METHODS The study gathered various specialists: anthropologists, archeologists, forensic pathologists, radiologists, pathologic physicians, and physicists. Imaging techniques were performed, before and after coronary opacification. Finally, hearts were autopsied and different histological samples were analyzed. RESULTS Only heart n°2 was too damaged to be studied. Heart n°3 was considered as normal using all investigation techniques. The study of Hearts n°s 4 and 5 revealed dilated cardiomyopathy while Heart n°1 showed important signs of diffuse hypertrophic cardiomyopathy. Different fibro lipid plaques were identified using imaging techniques, and were confirmed by histology. CONCLUSIONS The study of archeological soft tissues using modern imaging is possible if the material is well-preserved. This type of research can uncover principal findings, allowing scientists to establish diseases of ancient times.

Integrating Growth Variability of the Ilium, Fifth Lumbar Vertebra, and Clavicle with Multivariate Adaptive Regression Splines Models for Subadult Age Estimation

Subadult age estimation should rely on sampling and statistical protocols capturing development variability for more accurate age estimates. In this perspective, measurements were taken on the fifth lumbar vertebrae and/or clavicles of 534 French males and females aged 0–19 years and the ilia of 244 males and females aged 0–12 years. These variables were fitted in nonparametric multivariate adaptive regression splines (MARS) models with 95% prediction intervals (PIs) of age. The models were tested on two independent samples from Marseille and the Luis Lopes reference collection from Lisbon. Models using ilium width and module, maximum clavicle length, and lateral vertebral body heights were more than 92% accurate. Precision was lower for postpubertal individuals. Integrating punctual nonlinearities of the relationship between age and the variables and dynamic prediction intervals incorporated the normal increase in interindividual growth variability (heteroscedasticity of variance) with age for more biologically accurate predictions.