Magnetic resonance imaging of the clavicular ossification

Assessment of the degree of ossification of the medial clavicular epiphyseal cartilage is of vital importance in forensic age diagnostics of living individuals aged more than 18 years. To date, reference studies on the assessment of clavicular ossification using imaging procedures only relate to conventional radiography and computed tomography (CT). In this study, magnetic resonance (MR) scans of 54 sternoclavicular joints of bodies aged between 6 and 40 years were evaluated prospectively. All of the examined medial clavicular epiphyseal cartilages permitted an assessment of the degree of ossification. Stage 2 was first observed at the age of 15.0 years, the earliest age at which stage 3 was observed was 16.9 years, and stage 4 was first observed at the age of 23.8 years. The observed age intervals of the respective degrees of ossification correspond to the known data from X-ray and CT scan examinations. The achieved results should be examined with a larger number of cases. A modified examination protocol is required for the MR examination of the medial clavicular epiphyseal cartilage for the purpose of forensic age diagnostics of living individuals.     

Bone age determination based on the study of the medial extremity of the clavicle

The development of the medial clavicular epiphysis and its fusion with the clavicular shaft have been a subject of medical research since the second decade of this century. Computed tomography provides the imaging modality of choice in analyzing the maturation process of the sternal end of the clavicle. In a retrospective study, we analyzed normal development in 380 individuals under the age of 30 years. The appearance of an epiphyseal ossification center occurred between ages 11 and 22 years. Partial union was found from age 16 until age 26 years. Complete union was first noted at age 22 years and in 100 % of the sample at age 27 years. Based on these data, age-related standardized age distributions and 95 % reference intervals were calculated. Compared to the experience recorded in the relevant literature, there are several landmarks that show no significant change between different ethnic groups and different periods of publication; these are the onset of ossification, the time span of partial union, and the appearance of complete union. Despite the relatively long time spans of the maturation stages, bone age estimation based on the study of the development of the medial clavicular epiphysis may be a useful tool in forensic age identification in living individuals, especially if the age of the subject is about the end of the second or the beginning of the third decade of life (e. g. in determining the applicability of adult or juvenile penal systems). Another possible use is in identifying human remains whose age is estimated at under 30 years. Received 31 December 1997; Revision received 11 February 1998; Accepted 23 February 1998     

Studies on the time frame for ossification of the medial clavicular epiphyseal cartilage in conventional radiography

Radiological assessment of the degree of ossification of the medial clavicular epiphyseal cartilage plays a vital part in forensic age diagnosis of living adolescents and young adults. A total of 873 plain chest radiographs requested by the staff medical officer for members of staff aged 16–30 at the University Hospital Charité were evaluated retrospectively. Of these X-rays 699 permitted an assessment of ossification of at least 1 side of the clavicle. In addition to the customary stages (1: non-ossified epiphysis, 2: discernible ossification centre, 3: partial fusion, 4: total fusion) a stage 5 was also defined, characterised by the disappearance of the epiphyseal scar following total fusion. The earliest age at which stage 3 was detected in either gender was 16 years. Stage 4 was first observed in women at 20 years and in men at 21 years. In both genders, the earliest observation of stage 5 was at 26 years. It was concluded that plain chest radiographs can essentially be used to assess clavicular ossification. In practice, if overlap in posterior-anterior views impedes evaluation, a lateral view should also be taken to facilitate age estimation. In forensic practice the reference values of the present paper should be applied.     

Forensic age estimation in living subjects based on the ossification status of the medial clavicular epiphysis as revealed by thin-slice multidetector computed tomography

Determination of the stage of ossification of the medial clavicular epiphysis is a crucial part of age estimation in criminal proceedings when evaluating individuals with completed hand ossification. In order to ensure a maximum of accuracy in forensic age estimation practise, it is recommended to perform thin-slice CT scans; but to date there exist no reference data on the bone development of the region in question based on thin-slice computed tomography. In this retrospective study, the authors evaluated thin-slice multidetector CT images of 592 individuals aged between 10 and 35 years produced in the University Hospital of Münster. The ossification status of the medial epiphysis of the clavicle could be reliably determined in 502 cases using the classification of stages by Schmeling et al. In male individuals, stage 2 was first noted at age 14, in female individuals at age 13. Stage 3 was first achieved by male individuals at age 17, by female individuals at age 16. The occurrence of stage 4 was first found in both sexes at the age of 21. In either sex, the earliest observation of stage 5 was at age 26. The findings are basically in line with those from the only CT-based study on the subject in question using the same classification of five stages, except from the fact that in the present study, stage 5 first occurs at age 26, which is 4 or 5 years later than what was found in the CT study using 7 mm slices in the majority of cases. This vast difference may be explained through the partial volume effect occurring with thick-slice CT images by a visual deception of the epiphyseal scar occurring with stage 4.     

The value of sub-stages and thin slices for the assessment of the medial clavicular epiphysis: a prospective multi-center CT study

The clavicle plays an important role for forensic age estimation in living individuals, particularly with regard to the age of majority. The present prospective study aims to evaluate the age-dependent ossification process of the medial clavicular epiphysis in order to establish the clavicular sub-stages introduced in 2010 as well as the advantages and possibilities of thin-slice computed tomography (CT). For this purpose, 0.6 mm thin-slice CT scans of sternoclavicular joints of 572 bodies aged between 10 and 40 years were evaluated by means of two complementary classification systems: a five-stage system and a sub-staging system for the main stages 2 and 3. Assessment was possible in 493 cases. The results for stages 4 and 5 are in line with previous studies that found the ages of 21 years and 26 years, respectively, as minimum ages for these stages. Sub-stage 3c was first found at the age of 19 years in both sexes, thereby corroborating the value of this sub-stage as to statements about the age of majority. In comparison to other CT studies, stage 3a was first observed ~1 year earlier (16.4 years in males and 15.5 years in females). Stage 2c only occurred in 3 cases. In conclusion, the data corroborate the significance of diagnosing sub-stages as well as the value of thin-slice CT. For forensic practice, the concomitant and complementary use of both classification systems applied in this study can be recommended.     

Computed tomographic analysis of medial clavicular epiphyseal fusion for age estimation in Indian population

Forensic age estimation is a crucial aspect of the identification process. While epiphyseal fusion of long bones has been studied for age estimation since a long time, over the past few years, the role of medial clavicular epiphyseal fusion in age estimation is being explored. The medial clavicular epiphyseal fusion can be used to estimate age in young adults, and can also determine whether medicolegally significant ages of 16 and 18 years have been attained by an individual. The present study aimed at generating regression models to estimate age by evaluating the medial clavicular epiphyseal fusion in Indian population using Schmeling et al. and Kellinghaus et al. method, and to assess whether an individual’s age is over medicolegally significant thresholds of 16 and 18 years. Degree of ossification of the medial clavicular epiphysis was studied in CT images of 350 individuals aged 10.01–35.47 years. Significant statistical correlation (P < 0.001) was observed between the degree of fusion and the chronological age of the participants, with Spearman’s correlation (ρ) = 0.918 in females, and ρ = 0.905 in males. Regression models were generated using degree of ossification of medial end of clavicle of 350 individuals (147 females and 203 males) and these models were applied on a test set of 50 individuals (25 females and 25 males). Mean absolute error of 1.50 for females, 1.14 for males, and 1.32 for the total test set was observed when the variance between the chronological ages and estimated ages was calculated.     

Radiographic staging of ossification of the medial clavicular epiphysis

Determination of the stage of ossification of the medial clavicular epiphysis is a crucial part of forensic age estimation when evaluating living subjects over 18 years of age. In the present study, we comparatively assessed conventional radiographs and computed tomography (CT) scans of sternoclavicular joints used to perform forensic age assessments in 57 individuals undergoing criminal proceedings. With CT, it was possible to determine the ossification stage of all clavicles studied. In the case of conventional radiography, reliable assessment of ossification stage was not possible in 15 out of 114 clavicles studied due to the superimposition of other structures. Regarding agreement between the methods, both radiography and CT produced identical staging results in 97 out of 99 clavicular epiphyses. In two cases, however, ossification was classified as stage 2 by CT and as stage 3 by conventional radiography. Regarding stages 4 and 5, both methods produced identical staging results in all cases. In forensic age estimation practice, it is necessary that conventional radiographic reference studies be used for ossification stage classification by conventional radiography and that CT reference studies be used for ossification stage classification by CT. Further studies in dead bodies of known age are required to issue a recommendation as to whether conventional radiography using obtained in three planes or CT is the method of choice for the assessment of clavicular ossification.     

Ultrasound studies on the time course of clavicular ossification

When preparing forensic age estimates for living subjects over 18 years of age, it is crucial to evaluate the stage of ossification of the medial clavicular epiphysis. The establishment of radiation-free imaging techniques for assessment of clavicular ossification would be desirable in order to reduce the radiation exposure associated with forensic age estimations. In the present study, 84 right clavicles of test subjects 12–30 years of age were prospectively evaluated by means of ultrasound. Ossification stage classification was possible in 80 of the 84 medial clavicular epiphyses studied. In the remaining cases, stage classification was not possible due to the presence of developmental anomalies. The earliest ages at which the respective ossification stages were observed were 17.1 years for stage 2, 16.7 years for stage 3, and 22.5 years for stage 4. The age intervals observed for the ossification stages are consistent with the known data from radiological and computed tomography assessments. The present study results should be confirmed in a larger number of cases and with analysis of observer variability. Evaluation of medial clavicular epiphyseal ossification by ultrasound could ultimately be a rapid and economic non-ionizing diagnostic imaging procedure for forensic age estimation.     

Studies on the time frame for ossification of the medial epiphysis of the clavicle as revealed by CT scans

The authors retrospectively analyzed 629 CT images of patients aged between 15 and 30 years produced during multiple trauma diagnostics at the Unfallkrankenhaus Berlin. For the purposes of this study, the authors reliably determined the ossification status of the medial epiphysis of the clavicle in 556 cases, using the classification of stages by Schmeling et al. In both sexes, stage 2 was first noted at age 15. In male patients, the earliest occurrence of stage 3 was noted at age 17, in female patients at age 16. Stage 4 was first achieved by both sexes at age 21. Stage 5 was first noted in female patients at age 21 and in male patients at age 22, which is 4 or 5 years earlier than was observed by a comparable study using conventional radiographs. The partial-volume effect in computed tomography using the thick slice scanning mode was discussed as a possible explanation for this early visualization. The question of how slice thickness affects the age intervals between ossification stages identified by CT examinations should be examined in additional studies.     

胸肋锁骨肥厚综合征临床影像学诊断

目的探讨胸肋锁骨肥厚综合征的影像学诊断与鉴别诊断。资料与方法回顾性分析6例患者的X线平片和CT平扫资料。6例中,3例行工作站图像后处理,3例行单光子计算机体层(SPECT)扫描。结果6例均为双侧性胸-肋-锁骨区受累骨增粗,骨、骨髓腔及肋软骨密度增高。相邻关节间隙消失,呈骨性融合。CT见右侧第1肋软骨处假骨折线。SPECT扫描示胸锁关节区双侧较对称的放射性核素浓聚。结论胸肋锁骨肥厚综合征具有较典型的影像学特征,结合临床可做出正确诊断。CT成像在显示受累骨骨皮质、髓腔、韧带骨化、关节骨性强直等方面的改变优于X线平片和SPECT。     

Morphology as a cause for different classification of the ossification stage of the medial clavicular epiphysis by ultrasound, computed tomography, and macroscopy

The assessment of the ossification status of the medial clavicular epiphysis plays a decisive role in forensic age diagnostics to determine whether a person has completed his or her 18th or, respectively, 21st year of life. Currently, computed tomography is the gold standard method for age diagnostics of this kind. However, efforts are being made to establish non-ionizing methods, such as ultrasonography, predominantly, in an attempt to reduce the radiation exposure load of living persons. The present study is the first to score and to compare the ossification status of both medial clavicular epiphyses of the same subjects by sonography, computed tomography, and, in some of the cases, by macroscopy. Our study was conducted on five male corpses, ranging in age from 15.8–28.8 years. In the comparison of high-resolution sonography (frequency, 12–15 MHz) and thin slice computed tomography (slice thickness, 0.6 mm), performed separately for left and right clavicles, the results from these two methods differed in seven of ten cases. In six cases, the ossification stage of the medial clavicle, determined by sonography and classified according to Schulz et al. (2008), was scored higher than with computed tomography. In one case, it was rated lower. There was only one subject for whom both the sonographic and computed tomography findings agreed for both body sides.     

Beurteilung des Ossifikationsstadiums der medialen Klavikulaepiphysenfuge

In forensic age estimation of the living in criminal proceedings the radiological examination of the ossification status of the medial clavicular epiphysis permits an assessment with regard to the completion of 21 years of age. In the present study the authors prospectively comparatively analyzed 8 prepared samples of the sternoclavicular region of individuals aged 15–17 years obtained during autopsy by means of projectional radiography, thin-slice computed tomography and magnetic resonance imaging. In 6 out of 15 examined sternoclavicular joints the ossification stage of the medial clavicular epiphysis was in agreement in each of the three imaging methods used. In the remaining cases the ossification stage was assessed as either one stage higher or lower in one of the imaging methods than in the other two techniques. In five cases compared to CT, and seven cases compared to MR, projectional radiography showed a higher ossification stage than CT and MR imaging. In two cases projectional radiography resulted in the determination of a lower stage than in CT and MR imaging. MR scans showed a less advanced ossification stage than CT-based images in two cases. In the practice of age estimation modality-specific reference studies based on projectional radiography and computed tomography are to be applied in order to guarantee an adequate assessment of the ossification stage of the medial clavicular epiphysis.     

Enhanced possibilities to make statements on the ossification status of the medial clavicular epiphysis using an amplified staging scheme in evaluating thin-slice CT scans

Thin-slice computed tomography provides the imaging modality of choice in analysing the ossification process of the medial clavicular epiphysis for the purpose of forensic age diagnostics in the living in the course of criminal proceedings. The classification of the ossification stages by Schmeling et al. compass the emergence of an epiphyseal ossification centre (stage 2), the partial fusion of the epiphysis with the metaphysis (stage 3), the complete fusion of these osseous elements including a visible epiphyseal scar (stage 4), and the complete fusion without a visible epiphyseal scar (stage 5). In the present study, each of the ossification stages 2 and 3 was divided into an early, intermediate and late phase. The authors evaluated the thin-slice CT scans of 185 patients aged between 13 and 26 years. In all these cases, a stage 2 or 3 had been determined in a previous study. The late stage 3, which is characterized by a fusion between metaphysis and epiphysis completing more than two thirds of the former epiphyseal gap, first appeared at age 19 in both sexes. If a late stage 3 is found, it is therefore possible to substantiate that an individual has already reached the legally important age threshold of 18 years.     

Comparison of imaging planes during CT-based evaluation of clavicular ossification: a multi-center study

Determining the ossification stage of the medial clavicular epiphysis by computed tomography represents the currently recommended methodology for the question of whether a living individual has completed the 18th or 21st year of life. In the present study, thin-slice CT scans of 1078 sternoclavicular joints were reconstructed in axial and coronal image series and evaluated according to the two classification systems established for age diagnostics using the clavicle. Both image series (axial and coronal) were analyzed separately. When comparing the results of axial and coronal view, a different ossification stage was found in 35.6% of the clavicles. The results suggest an influence of the imaging plane on the process of stage determination. In order to further approximate the three-dimensional and asymmetrical structure of the epiphyseal ossification center, the usage of at least two different reformation types may be recommended. In practice, only those reference studies should be applied which exactly employed the same number and orientations of the reformation types that are going to be used in the respective routine case.

     

Sonographic assessment of the ossification of the medial clavicular epiphysis in 616 individuals

Establishing radiation-free imaging methods for the assessment of clavicular ossification in forensic age determination is desirable as it reduces radiation exposure in living individuals. For this purpose the stage of ossification of the right medial clavicular epiphysis was determined prospectively using sonography in 309 male and 307 female healthy volunteers. The classification of stages according to Schulz et al. was used for this purpose. Stage 2 was first noticed at the age of 14.4 years in males, and at the age of 14.1 years in females. Stage 3 was first achieved by males at the age of 17.6 years and by females at the age of 17.4 years. Stage 4 first occurred in males at the age of 19.3 years and at the age of 18.9 years in females. The mean age for stage 1 was 13.6 years. The mean age of stage 2 ranged between 17.3 and 17.6 years. For stage 3 the mean age varied from 20.7 to 21.2 years, and for stage 4 from 23.3 to 23.5 years. It was concluded that sonographically determined stage 4 clavicular ossification provides evidence for the completion of the nineteenth year of life in males and the eighteenth year of life in females. In order to increase the reliability of age determination using this method it is recommended that findings be recorded by at least two experienced independent examiners who then reach a consensus.     

Influence of the examiner’s qualification and sources of error during stage determination of the medial clavicular epiphysis by means of computed tomography

Computed tomography (CT) of the medial clavicular epiphysis has been well established in forensic age estimations of living individuals undergoing criminal proceedings. The present study examines the influence of the examiner’s qualification on the determination of the clavicular ossification stage. Additionally, the most frequent sources of error made during the stage assessment process should be uncovered. To this end, thin-slice CT scans of 1,420 clavicles were evaluated by one inexperienced and two experienced examiners. The latter did the evaluations in consensus. Two classification systems, a five-stage system and a substaging system for the main stages 2 and 3, were used. Prior to three of his six assessment sessions, the inexperienced examiner was specifically taught staging of clavicles. Comparison of the examiners’ results revealed increasing inter- and intraobserver agreements with increasing state of qualification of the inexperienced examiner (from κ=?0.494 to 0.674 and from κ=?0.634 to 0.783, respectively). The attribution of a not-assessable anatomic shape variant to an ossification stage was identified as the most frequent error during stage determination (n=?349), followed by the overlooking of the epiphyseal scar defining stage 4 (n=?144). As to the clavicular substages, classifying substage 3a instead of 3b was found to be the most frequent error (n=?69). The data of this study indicate that κ values must not be considered as objective measures for inter- and intraobserver agreements. Furthermore, a high degree of specific qualification, particularly the knowledge about the diversity of anatomic shape variants, appears to be mandatory and indispensable for reliable evaluation of the medial clavicular epiphysis.     

Age estimation from clavicular epiphyseal union sequencing in a Northwest Indian population of the Chandigarh region

Medial clavicular epiphysis is the long bone epiphysis to fuse last and therefore, is useful for estimating age in the post-pubertal period. Age estimation was done from clavicles obtained from 343 cadavers (252 males and 91 females) of known age. The data was subjected to statistical analysis to see whether the difference obtained in the various ages was significant or not. Commencement of fusion was seen as early as 18 years of age in both male and female clavicles. No clavicle showed complete fusion until the age of 22 years. Complete fusion of the medial end of the clavicle was seen latest at 32 years in the male clavicles while the same was observed at 31 years in the female bones, i.e., the medial epiphysis of female clavicles fused one year earlier than their male counterparts. Advanced stages of clavicular epiphyseal union were seen in most of the clavicles after 24 years of age in females and 23 years of age in males. No significant difference was noticed in both sexes for the right and left clavicles as regards to the occurrence of various stages of epiphyseal union.     

Morphologie der sonographisch vollständig fusionierten medialen Claviculaepiphyse

Background

Assessment of the ossification stage of the medial clavicular epiphysis is an important forensic tool in the age estimation of living subjects, in particular to determine whether the age of majority, i.?e. 18 or 21 years, has been reached. Currently, computed tomography is the gold standard modality for these assessments. Recently, there have been endeavors to establish sonography as a modality in age diagnostics as it is widely available and does not expose subjects to radiation. The results of these studies, however, suggest that it can be particularly difficult to differentiate stage 1 (ossification process not yet begun) and stage 4 (complete union) epiphyses by ultrasound.

Aim

The object of the present study was to identify morphological characteristics from medial clavicle epiphyses classified as stage 4 by high-frequency sonography that could serve as indicators that the epiphyses of these clavicles were in actual fact still in stage 1.

Material and methods

The medial clavicular epiphyses of 410 subjects aged between 14 and 26 years, were examined by high-frequency sonography and classified to an ossification stage. All sonograms of clavicles classified as stage 4 were retrospectively analyzed in three standardized scanning planes for the sonographic morphology in terms of the shape and development of the convex clavicle end that characterizes this stage.

Results

A total of 125 clavicles were evaluated. While the contour of the medial end of the clavicle described a sharp downward turn in the sonograms from subjects over 20 years old, the contour described only a gentle downward incline in the younger subjects. Pestle or stamp-shaped medial clavicle ends were observed only for caudal scanning positions.

Conclusion

Not every clavicle that appeared to have a convexly rounded end in all scanning planes necessarily has to have a fully fused epiphysis. The distribution of findings in the present study suggests that clavicle contours that describe only a gentle downward incline, as well as those with contours reminiscent of a pestle or stamp, do not necessarily correlate with full epiphyseal union. Thus, the epiphyseal ossification stages 1 and 4 cannot be reliably differentiated by sonography on the basis of the morphological characteristics compiled in this study.

     

Scintigraphic and CT findings of Tietze's syndrome: report of a case and review of the literature

A case of Tietze's syndrome is reported. A 43-year-old woman, who had experienced right anterior chest pain and tender swelling of the right first costosternal junction for seven months, showed increased accumulation of the right first, the right fourth, and the left first costochondral junction on bone imaging. Ga-67 imaging showed increased accumulation at the right first costosternal junction. CT showed sclerosis of the sternal manubrium, partial calcification of costal cartilage, and soft tissue swelling. Biopsy of the right first costal cartilage showed chronic inflammation with fibrosis and ossification. Increased uptake of bone gallium imaging is consistent with Tietze's syndrome.     

The influence of slice thickness on assessment of clavicle ossification in forensic age diagnostics

Computed tomography scans originally obtained to assess the ossification status of the medial clavicular epiphyses of 40 live subjects for forensic age estimation purposes were analysed. From the data acquired we reconstructed images with slice thicknesses of 1, 3, 5 and 7 mm, and based on the classification of stages by Schmeling et al. (Int J Legal Med 118:5–8, 2004), we determined the ossification stage for each reconstructed slice thickness, separately for both sides. Of the 80 clavicular epiphysial plates examined, seven displayed slice-thickness-dependent differences at certain ossification stages. In one case a slice thickness of 1 mm led to a different diagnosis of the ossification stage than a slice thickness of 3 mm, in three cases the diagnoses differed between the slice thicknesses of 3 and of 5 mm, and in another three cases, between 5 and 7 mm. We therefore conclude that for age estimation purposes, the slice thickness should be 1 mm to ensure maximum accuracy and diagnostic reliability.