Research on Auditory Long Latency Response in Normal Hearing Subjects / 法医学杂志

OBJECTIVES@#To explore the characters and the relationship among latency response, amplitude and sound stimulus intensity of auditory long latency response（ALR）, and to investigate the significance of ALR applied in auditory threshold prediction.@*METHODS@#Total 46 subjects （92 ears） with normal hearing were tested by ALR. The ALR waves of the subjects were elicited by 5 sound stimulus intensity according to the order of 70, 50, 30, 20 and 10 dB nHL. By making N₁ wave and P₂ wave, the values of 3 observed indexes （the latencies of N₁ wave and P₂ wave and N₁-P₂ amplitude） were obtained, and the variation trend of the observed indexes were statistically analyzed. The differences in the frequency of the indexes were observed.@*RESULTS@#The rate of ALR waves from 46 subjects （92 ears） with normal hearing was 100%. The latencies of N₁ wave and P₂ wave delayed gradually and N₁-P₂ amplitude declined with sound stimulus intensity descending.@*CONCLUSIONS@#In suitable conditions, ALR is a stable technology for hearing thresholds prediction. The relation between sound stimulus intensity and latency of N₁ wave, latency of P₂ wave and N₁-P₂ amplitude of ALR plays an important part in auditory thresholds assessment.

Forensic Medical Assessment for Neurologic Erectile Dysfunction: 58 Case Reports / 法医学杂志

To introduce the approaches and procedures of neurologic erectile dysfunction (ED) assessment in our institute, and evaluate the neurologic investigation by making an analysis of 58 cases. Diagnostic criteria of neurologic ED: nervous system injuries or diseases, abnormal clinical symptoms and signs, electrophysiological abnormalities of nervous system, abnormal results of nocturnal penile tumescence and rigidity (NPTR) (penis rigidity <60% and lasting time <10 minutes). In the group of 20 patients with the injuries of the brain, spinal cord or spinal root nerves, pudendal cortical somatic evoked potential (PCSEP), sacral reflex latency (SRL), pudendal-to-cortical motor evoked potential (PCMEP), penile sym- pathetic skin responses (PSSR) and NPTR showed abnormality by 45%, 20%, 20%, 85% and 85%, re- spectively. In 38 patients with the injuries of pelvic fracture with urethra break, PCSEP, SRL, PCMEP, PSSR and NPTR showed abnormality by 24%, 5%, 20%, 92% and 66%, respectively. In the former, 35% were identified to have severe ED, and 50%, moderate ED; in the latter, 21%, to have severe ED, 13%, medium ED, and 37%, light ED. The approaches and procedures were proved to possess excellent specificity and reliability in the assessment of neurological ED.

Automated assessment of developmental levels of epiphysis by support vector machine / 法医学杂志

OBJECTIVE@#To realize the automated assessment of the levels of epiphysis of distal radius and ulna by support vector machine (SVM).@*METHODS@#The X-ray films of the left wrist joints were taken from 140 teenagers aged from 11 to 19 years old as training samples. The levels of epiphysis of distal radius and ulna were divided into five developmental levels. Each level contained 28 samples. Another 35 cases were selected as independent verifying samples. SVM classification models of the five developmental levels of epiphysis of distal radius and ulna were established. The internal cross validation was made by leave one out cross validation (LOOCV), while the external validation was made by histogram of oriented gradient (HOG), and then the accuracy (PA) of testing results was calculated, respectively.@*RESULTS@#The PA of SVM, LOOCV and HOG of distal radius epiphyseal level were 100%, 78.6%, and 82.8%, respectively; whereas the PA of SVM, LOOCV and HOG of distal ulna epiphyseal level were 100.0%, 80.0% and 88.6%, respectively.@*CONCLUSION@#The SVM-based automatic models of the growth stage of distal ra- dius and ulna appear to have certain feasibility, and may provide a foundation for software development of bone age assessment by forensic medicine.

Coronary angiography of in vitro porcine heart using MSCT / 法医学杂志

OBJECTIVE@#To establish standardized methods and parameters of the isolated heart coronary angiography through the experiment of in vitro porcine heart by MSCT.@*METHODS@#Based on different perfusion volume (50, 60 and 70 mL) and different perfusion-imaging time (5, 10 and 20 min), the in vitro porcine coronary artery was injected liposoluble and water-soluble contrast agents using remodel angiography equipment and scanned by MSCT. And the 3D image results were compared. The images were recorded and evaluated by 2 radiologists and analyzed by statistical software.@*RESULTS@#Liposoluble contrast agent affected the images by damaging and infiltrating the fats around the coronary artery, while the water-soluble contrast agent didn't affect the images. The groups with 60 mL or 70 mL perfusion and 5 min perfusion-imaging time had the best images.@*CONCLUSION@#The suitable parameters of the angiography lay the foundation of postmortem coronary angiography.

Electroretinogram and histopathologic changes of the retina after methanol intoxication / 法医学杂志

In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication, 35 rats were divided randomly into five groups administrated with saline, 3-day high dose, 7-day high dose, 3-day low dose and 7-day low dose methanol separately. The retinal function of each group was assessed by flash electroretinogram (F-ERG) 3 and 7 days after methanol poisoning. The microstructure and ultrastructure of the retina were observed at the same time. The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning, which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG. These injuries were aggravated 7 days after poisoning. Meanwhile, the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning, but there were no further worsening tendency 7 days after poisoning. The retinal histological analysis showed cellular edema, heteromorphy and disarrangement, tissular loosen of the inner nuclear layer and photoreceptors layer. The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer. The low-dose methanol intoxication only caused transient damage of the retina. Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells. The mitochondrial damage developed from outer layer to inner layer of the retina.

Progress in thin layer CT scan technology in estimating skeletal age of sternal end of clavicle / 法医学杂志

It is practical value for determination the teenagers whether the age is full of the legal responsibility age of 18 years old or not by estimating skeletal age of sternal end of clavicle. The traditional methods mainly based on X-ray radiography. However, sternal end of clavicle and adjacent lung, bronchus, sternum, rib, transverse process of thoracic vertebra are overlapped each other. As a result of overlapping, there will be obtained false negative or positive film reading results when according to X-ray observation of epiphyseal growth of sternal end of clavicle, which directly affect the scientificalness and accuracy of estimating of skeletal age. In recent years, the scholars at home and abroad have started to use thin layer CT scan technology to estimate skeletal age of the sternal end of clavicle. With the 2D and 3D CT recombination technology, the accuracy of the film reading distinctly improves by making the shape, size and position of epiphysis displayed clearly. This article reviews the application and research progress of thin layer CT scanning technology in estimating skeletal age of sternal end of clavicle at home and abroad, analyzes the superiority and value of thin layer CT scan technology, which applied to skeletal age of sternal end of clavicle.

The staging method of sternal end of clavicle epiphyseal growth by thin layer CT scan and imaging reconstruction / 法医学杂志

OBJECTIVE@#To establish a CT staging method of sternal end of clavicle epiphyseal growth for teenagers by thin layer CT scan, multiplanar reconstruction (MPR) and volume reconstruction (VR) technologies.@*METHODS@#The CT imaging characteristics, which collected from 460 teenagers (aged from 15 to 25) in East and South China, were studied through both sternal ends of clavicles' imagings by thin layer coronal CT scan and axial CT scan, MPR and VR technologies. The parameters of sternal end of clavicle including the longest diameter of epiphysis, the longest diameter of metaphysis, their length ratio, area of epiphysis, area of metaphysis, and their area ratio were measured and calculated in order to establish new classification.@*RESULTS@#Based on the staging method of Schmeling, integrating the CT imaging reconstruction information of sternal end of clavicle, the new classification of sternal end of clavicle epiphyseal growth were divided into 1 to 5 stages, and stage 2 and stage 3, respectively, contained a, b and c sub-classification.@*CONCLUSION@#This new classification has merits of large sample size, wide age range and easy operability. By using CT imaging reconstruction techniques and analyzing the data which closely related to sternal end of clavicle epiphyseal growth of teenagers, the feasibility of the staging method could be increased.

Bone development trend in the knee joint of Tibetan teenagers in Aba Prefecture of Sichuan Province / 法医学杂志

OBJECTIVE@#To discuss bone development trend in the knee joint of Tibetan teenagers in Sichuan province and to effectively update the database for estimating the living age of Tibetan teenagers in terms of bone age of the knee joint.@*METHODS@#Radiographs including epiphysis of distal femur, proximal tibia and proximal fibula were taken from 483 Tibetan male and female teenagers aged from 14 to 19 years old in Aba prefecture of Sichuan province in order to observe epiphyseal growth situation. The descriptive data of the epiphyseal closure ages of these teenagers' knee joints were statistically analyzed by SPSS 16.0 software.@*RESULTS@#The distal femur epiphyseal closure occurred earliest, while the proximal fibula epiphyseal closure occurred latest. The epiphyseal growth of knee joints of females occurred about one year earlier than that of males.@*CONCLUSION@#The forensic information and data related to Tibetan teenagers' bone age identification should be updated regularly. These results provide potential value for the practice of forensic medicine, anthropology and clinical medicine.

Mathematical models for teenager's living age evaluation based on CT image of medial clavicular epiphysis / 法医学杂志

OBJECTIVE@#To explore the correlation between volume rendering (VR) statistics of medial clavicular epiphysis and living age, and establish the mathematical models for living age evaluation using the CT image of medial clavicular epiphysis based on the growth rules of osteoepiphysis of medial clavicle.@*METHODS@#The CT images of the medial clavicles from 795 teenagers aged 15-25, 387 males and 408 females, were collected in East and South China. VR 3D images were reconstructed from 0.60 mm-thick slice CT images. The epiphyseal diameter, sternal end diameter, and their respective diameter ratio (the left: X1; the right: x3); epiphyseal area, sternal end area, and their respective area ratio (the left: x2; the right: x4), were measured and calculated. All these observations were analyzed using SPSS 19.0 statistical software. The statistical differences in gender and age were analyzed by Mann-Whitney U test. The mathematical models were established using least square. Sixty trained subjects, 30 males and 30 females, were tested to verify the accuracy of the established mathematical models.@*RESULTS@#In the group of same age, x1 showed significant difference in gender; the same results were observed in x2, x3, and x4, which suggested that the growth rules of osteoepiphysis of medial clavicle were highly correlated with living age. The accuracy of these mathematical models were all above 67.6% (+/- 1.0 year) and 78.5% (+/- 1.5 year).@*CONCLUSION@#The mathematical models with reasonable accuracy could be manageable in practice to confirm the conclusion of the atlas method. The current study can contribute to the single skeletal age evaluation.

Application of MSCT's coronary artery calcification score in evaluation of sudden death caused by coronary artery disease / 法医学杂志

OBJECTIVE@#To access application value of multi-slice spiral computed tomography (MSCT) and coronary artery calcium scoring (CACS) in investigation the coronary artery disease (CAD), and to explore the effective way of virtual autopsy to evaluate the sudden death due to CAD.@*METHODS@#Nine cases of sudden cardiac death were collected to analyze MSCT before the autopsy. The quantitative analysis of the degree of coronary artery calcium was made by Agatston's method. The CACS of all the subjects were calculated based on the diagnostic criteria for CAD, in which calcium scoring was more than 400. The results of CACS were compared with that of the autopsy.@*RESULTS@#Only 2 cases got the high calcium scoring which were more than 400 in the 9 cases died of CAD confirmed by the autopsy. The prediction rate of CACS for CAD was only 22.2%. Pulmonary edema of different severity was found in both autopsy and MSCT. There was a higher morbidity rate in the left anterior descending of coronary artery than the other branches.@*CONCLUSION@#Obvious calcification of coronary artery can be detected by MSCT and calculating CACS. To detect subtle calcification needs other technologies such as postmortem angiography.

Reliability study on quantitative detection of extensor digitorum brevis strength with needle electromyography and nerve conduction / 法医学杂志

OBJECTIVE@#To study the objectivity and reliability of needle electromyography and nerve conduction for detection of musculus extensor digitorum brevis strength, which may provide a basis for establishing a quantitative detection of muscle strength in forensic clinical study.@*METHODS@#Forty-four healthy people were enrolled as the subjects, and during toe dorsiflexion, the following items including needle electromyography indexes, motor unit potential (MUP) amplitude, MUP count, recruitment reaction type, and nerve conduction detection indexes, compound muscle action potential (CMAP) amplitude, CMAP latent period and motor nerve conduction velocity (MNCV), were simultaneously detected under the cooperation and disguise condition.@*RESULTS@#Under the cooperation condition, regardless of the same operator or different operators, there were good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, while there were normal test-retest reliabilities in MUP count and recruitment reaction type and the repeatability of the same operator was slightly better than the repeatability between different operators. Under the disguise condition, test-retest reliabilities of MUP amplitude, CMAP amplitude, CMAP latent period and MNCV were relatively high, while test-retest reliabilities of MUP count and recruitment reaction type were relatively low.@*CONCLUSION@#There are good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, which can be conducive to comparison between different operators and results at various times; MUP count and recruitment reaction type, which can be easily affected by subjectivity of operators and examinees, can be used to differentiate whether an examinee disguises or not. The indexes used to objectively judge muscle strength remain to be further investigated.

Analysis of variation of Han male adolescent bone development in Hainan, Henan and Zhejiang provinces / 法医学杂志

OBJECTIVE@#To study the difference of bone development of the Han male adolescents in Hainan, Henan and Zhejiang provinces.@*METHODS@#All radiographs including sternal end of clavicle, pelvis and six main bone joints taken from 877 Han male adolescents aged between 12.00 and 20.00 in Hainan, Henan and Zhejiang provinces were reviewed. Twenty-four indices of skeletal development were analyzed based on "The Grading Standards" of skeletal growth of teenagers and then the bone age were calculated using mathematical model functions. The ratios of the bone age and the chronological age were then analyzed by statistical software.@*RESULTS@#The development of Hainan male adolescents' skeleton were about 1.09 years and 1.26 years earlier than that in Henan and Zhejiang at the age group of 12.00-12.99 years. The development of Hainan male adolescents' skeleton were about 0.70 years and 1.38 years earlier than that in Henan and Zhejiang at the age group of 13.00-13.99 years, while the development of Henan male adolescents' skeleton were about 0.68 years earlier than that in Zhejiang in this age group. The development of Hainan male adolescents' skeleton were about 0.79 years later than that in Henan at the age group of 18.00-18.99 years. The development of Hainan male adolescents' skeleton were about 0.70 years and 0.95 years later than that in Henan and Zhejiang at the age group of 19.00-20.00 years.@*CONCLUSION@#There are significant differences in the skeleton development of Han male adolescents between the provinces of Hainan, Henan and Zhejiang. These results provide potential value for the practice of forensic medicine, anthropology and clinical medicine.

Comparisons among different reference values of nerve conduction velocity in forensic appraisal / 法医学杂志

OBJECTIVE@#To provide the evidences for the choice of normal reference value of nerve conduction velocity (NCV) in clinical forensic appraisal.@*METHODS@#One hundred and fourteen cases with normal peripheral nerve and 155 cases with injured peripheral nerve were collected. The NCV of homonymous nerves in two limbs were detected. In the normal cases, the NCV of the left limbs were used as the normal reference values. The NCV of the right limbs were compared with that of left limbs, the commendatory normal reference values from Beijing Xiehe Hospital and Shanghai Huashan Hospital. In the injured cases, the results of NCV in injuried limbs were compared with the results of healthy limbs and the reference values from Beijing Xiehe Hospital and Shanghai Huashan Hospital.@*RESULTS@#In the normal group, there was no statistical difference between the left and right limbs in NCV results of homonymous nerve (P > 0.05). The false positive rates (FPR) were 0, 11.4% and 5.2% for three choices normal reference respectively. The false negative rates (FNR) were 0, 9.7% and 12.3% for three choices normal reference in injuried group. Thee false negative cases were all slight nerve injury.@*CONCLUSION@#The reference value of self-control method could decrease the FPR of normal cases and FNR of injured cases. In clinical forensic appraisal of peripheral nerve, the nerve condition study results from healthy homonymous nerve should be regarded as the reference value at first, supplemented by reference values from clinical labs.

Progress in diagnosis of neurogenic erectile dysfunction / 法医学杂志

Recently, with application of evoked potentials technology in the test of somatic and autonomic nerves, quantitative sensory testing in the detection of small nerve fiber function, and functional magnetic resonance imaging in the detection of senior central function, the detection of neural function has become more accurate. This article reviews the progress and application of diagnostic methods about neurogenic erectile dysfunction in order to provide a reference for forensic diagnosis and research 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 1 709 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 1 year 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.

Application of needle electromyography and nerve conduction study in forensic appraisal / 法医学杂志

OBJECTIVE@#To explore the application value of needle electromyography (EMG) and nerve conduction study (NCS) in the forensic appraisal; to provide scientific basis for establishing normative and unified assessment methods of the peripheral nerve study in forensic medicine.@*METHODS@#One hundred and sixty-four samples with injured peripheral nerve (injury group) and 138 samples with normal peripheral nerve (control group) were collected and tested with methods of EMG and NCS respectively. The relevance rate of two methods were compared and statistical analysis was performed.@*RESULTS@#In the injury group, there was no statistical difference on the relevance rate between the application of EMG and that of NCS (P > 0.05). In the control group, there was no statistical difference on the negative rate between the two methods (P > 0.05). The false negative rate of the injury group and the false positive rate of the control group were both 0% when using the two methods together.@*CONCLUSION@#When the injured peripheral nerve in forensic appraisal is in doubt, application of both EMG and NCS could disclose truth from falsehood. The accuracy and credibility of identification results could be enhanced.

Assessment of a sudden death case due to coronary artery disease based on the PMCT and forensic autopsy / 法医学杂志

It is never an easy thing to diagnose heart vascular disease only depending on the unenhanced postmortem computed tomography (PMCT). This article reported a case of sudden natural death after the complaint of anterior chest pain in which coronary artery calcification (CAC) was clearly displayed using PMCT scan. The entire coronary artery system was almost reconstructed via multiplanar reformation (MPR) and volume-rendering reconstruction (VR), and the total calcium score of the coronary arteries was obtained with CaScoring automatic analysis software. The results showed that CAC was conspicuous; the total calcium score was 640.3, considerably higher than 400. The pulmonary ground-glass opacity (GGO) and small amount of fluid both in the subglottic trachea and main bronchi were also found. The imaging results confirmed those of autopsy. In addition, the results concluded that PMCT might serve as an invaluable adjunct to the classic autopsy procedure.

Application of slow vertex response in auditory threshold prediction for subjects with hearing loss / 法医学杂志

OBJECTIVE@#To study the value of slow vertex response (SVR) in the evaluation of hearing loss by comparing the hearing thresholds acquired with SVR and pure tone audiometry (PTA).@*METHODS@#Twenty-five subjects (40 ears) with sensorineural hearing loss were tested by PTA and SVR. According to the thresholds of PTA, these ears were subdivided into mild, moderate and severe hearing loss groups, and rank sum test was performed on the thresholds of SVR and PTA for all the hearing loss groups. Then, the correlation between PTA thresholds and SVR thresholds was analyzed and the mathematical models were established for predicting behavioral thresholds by the thresholds of SVR.@*RESULTS@#At four test frequencies (0.5, 1, 2 and 4kHz), the thresholds of SVR had high correlations with thresholds of PTA. Four liner regression equations were established, and the correlation coefficient(r) were 0.971, 0.976, 0.957 and 0.928, respectively (P < 0.05). Back substitution test showed that the liner regression equations would be an easy method for estimating the behavior thresholds.@*CONCLUSION@#The behavioral threshold can be well judged and evaluated by the liner regression equations established with SVR thresholds.

Application of quantitative temperature testing in diagnosis of neurogenic erectile dysfunction / 法医学杂志

OBJECTIVE@#To explore the application of quantitative temperature testing (QTT) in forensic identification and clinical diagnosis of neurogenic erectile dysfunction (NED).@*METHODS@#TSA-II-NeuroSensory Analyzer was used to measure the thresholds of four kinds of sensory, including cold, cold pain, heat, heat pain, in 22 normal and 35 NED patients at dorsal glans (DG), left thigh interior (LTI) and left thenar (LT). To calculate the relative thresholds of the sensory mentioned above between DG and LTI (DG/LTI), and between DG and LT (DG/LT). Then to analyze those thresholds and the relative thresholds.@*RESULTS@#NED group showed significant higher threshold than the normal group in DG-heat, DG-heat pain, LTI-heat, LTI-heat pain, DG/LTI-heat, DG/LT-heat, DG/LT-heat pain (P < 0.05).@*CONCLUSION@#The threshold of QTT at dorsal glans could be used as an accessory indicator in forensic medicine and clinical diagnosis of NED.

Skeletal age estimation of sternal end of clavicle in Sichuan Han nationality youth using thin-section computed tomography / 法医学杂志

OBJECTIVE@#To explore the growth status of epiphysis of sternal end of clavicle using thin-section computed tomography (CT) and to study the relationship between the status and the chronological age of Sichuan Han nationality youth.@*METHODS@#According to the Schmeling's report and the age range of our samples, the ossification status of medial clavicle epiphysis was classified as four stages. CT films of 565 patients between 15 and 25 years were studied based on the classification and analyzed statistically.@*RESULTS@#There was no statistical difference between the sexes (P > 0.05). The calculated empiric distribution function showed that 100% of stage 1 patients were under 18 years, 75% of stage 2 patients were under 18 years, 94.5% of stage 3 patients were over 18 years, and 100% of the stage 4 patients were over 20 years, respectively.@*CONCLUSION@#The ossification of medial epiphysis of the clavicle for those around 18 years has certain regular. These characteristics can be used for forensic identification of the skeletal age, especially 18 years, which is the criminal responsibility age.