Automated Assessment of Developmental Levels of Epiphysis by Support Vector Machine / 法医学杂志

Objective To realize the autom ated assessm ent of the levels of epiphysis of distal radius and ulna by support vector m achine (SVM). Methods The X-ray film s of the leftwrist jointswere taken from 140 teenagers aged from 11 to 19 years old as training sam ples. The levels of epiphysis of distal radius and ulnawere divided into five developm ental levels. Each level contained 28 sam ples. A nother 35 cas-eswere selected as independent verifying sam ples. SVM classification m odels of the five developm ental levels of epiphysis of distal radius and ulnawere established. The internal cross validationwas m ade by leave one out cross validation (LOOCV ),while the external validationwas m ade by histogram of orient-ed gradient (HOG), and then the accuracy (PA ) of testing resultswas calculated, respectively. Results The PA of SVM, LOOCV and HOG of distal radius epiphyseal levelwere 100%, 78.6%, and 82.8%, respec-tively;whereas the PA of SVM, LOOCV and HOGof distal ulna epiphyseal levelwere 100.0%, 80.0%and 88.6%, respectively. Conclusion The SVM -based autom atic m odels of the growth stage of distal ra-dius and ulna appear to have certain feasibility, and m ay provide a foundation for software developm ent of bone age assessm ent by forensic medicine.

The Subtle Anatomical Structures of Normal Nasal Bone in MSCT Image and Forensic Identification / 法医学杂志

Objective To summarize the subtle anatomical structures of the normal nasal bone in mul-ti-slice spiral CT (MSCT) image through the observation of the three-dimensional images. Methods One hundred and twenty volunteers who had no nasal trauma and disease history were collected. The nasal was scanned using MSCT. Raw data was reconstructed into bone window images (slice thickness 0.6 mm, slice interval 0.5 mm), and then the images were imported into Syngo Imaging XS software to recon-struct three-dimensional images and to summarize the nasal bone ’s subtle anatomical structures. Results The subtle anatomy of normal nasal bone generally included four seams, two holes and one edge. The four seams were left and right nasal-maxillary suture, nasal-frontal seam, and internasal suture. The two holes were left and right nasal aperture. The edge of the nasal was the lower edge of the nasal bone. In addition, there was suture bone in internasal suture in some normal nose. The nasal aperture mostly was hole-like, but some nasal apertures were line shape. The nasal edge can be divided into flat type, wave-shaped type, inverted spike type, hook-shaped type and others. Conclusion The anatomy diversity and individual differences in nasal bone are large. MSCT and three-dimensional image reconstruction techniques, combined with the history of trauma could distinguish between the normal anatomy and fractures.

Mathematical Models of the Teenager’s Skeletal Age Evaluation Based on CT Scan and Imaging Reconstruction of Medial Clavicular Epiphysis / 法医学杂志

Objective To explore the correlation between CTvolume rendering (VR) statistics and living age and to build the mathematical models for skeletal age evaluation based on the grow th rules of medi-al clavicular epiphysis of teenagers in China. Methods The thin layer CTscan and VR3D imaging re-construction of both sides of sternal ends of clavicles were exam ined for 684 teenagers aged from 15 to 25 in East and South China. The parameters of sternal end of clavicle including the longest diameter of epiphysis, the longest diameter of metaphysis, their length radio, area of epiphysis, area of meta-physic, their area ratio, and other data were measured and calculated in order to establish mathematical models of skeletal age evaluation. Fifty trained subjects were tested to verify the accuracy of the math-ematical models. Results In the same age group, the length ratio and the area ratio had significant dif-ference in genders (P<0.05). The established mathematical models showed that the grow th rules of medial clavicular epiphysis were highly correlated with the living ages. The accuracies of these models were higher than 70.5% (±1.0 year) and 82.5% (±1.5 year). Conclusion The mathematical models have easy operability and high accuracy. It can be used to confirmand sustain the conclusion of atlas method. M eanw hile, it is of great significance to study the other single skeletal age evaluation in the future.

Long-Term Trend of Bone Development in the Contemporary Teenagers of Chinese Han Nationality / 法医学杂志

Objective To further improve the accuracy of bone age identification using the time of secondary ossification center appearance and epiphyseal fusion of 7 joints to estimate the age of living individuals.Methods DR films were taken from 7 parts including sternal end of clavical and the left side of shoulder,elbow,carpal,hip,knee and ankle joints of 1709 individuals who came from eastern China,central China and southern China,whose ages were between 11.0 and 20.0 years.From those 7 joints 24 osteal loci were selected as bone age indexes,which could better reflect age growth of teenagers.The characteristics of secondary ossification center appearance and epiphyseal fusion were observed,and the mean and age range of secondary ossification center appearance and epiphyseal fusion were calculated.Results The fusion time of the 24 epiphyses were advanced at different degrees,the most obvious epiphyses the sternal end of clavicle,scapular acromial end,distal end of the radius,distal end of the ulna,iliac crest,ischial tuberosity,the upper and lower end of tibia and fibula.The appearance time of sternal end of clavicle,scapular acromial end,iliac crest and ischial tuberosity epiphyses were all found to be after the age of 12,and the female's age,approximately 1year ahead of schedule in comparison with the male's.Conclusion The relevant forensic information and data for bone age identification should be updated every 10-15 years so as to provide accurate and objective evidence for court testimony,conviction and sentencing.