1.Longitudinal left myocardial function in patients with latent autoimmune diabetes in adults quantitatively assessed by strain rate imaging
Mengjun TANG ; Qichang ZHOU ; Zhiguang ZHOU ; Danming CAO ; Yi TAN ; Changlin MEI
Chinese Journal of Ultrasonography 2009;18(1):22-26
Objective To discuss the clinical value of strain rate imaging in quantitatively evaluating segmental myocardial function of left ventricle in latent autoimmune diabetes in adult(LADA).Methods Thirty LADA without complication(LADA group),30 LADA patients with hypertension and normal geometric left ventricle(LADA+NLVH group)and 30 healthy people(control group)were enrolled.All patients had normal ejection fraction,normal fractional shortening and no cardiac symptoms.The strain rate in systolic,early and later diastolic periods were obtained from 3 consecutive heartbeats in 16 segments respectively.The parameters were quantitatively analyzed between the three groups.Results Compared with the control group,all of the measured parameter of LADA and LADA+NLVH were significantly lower(P<0.05 or P<0.01).Although the mean strain rate in early and later diastolic periods decreased significantly in LADA+NLVH group than in LADA group(P<0.05),there was no significant difference in the mean systolic strain rate between the two groups (P>0.05).Conclusions Strain rate imaging provides a sensitive and accurate tool to assess the left ventricular myocardial performance in patients with LADA.
2.The imaging findings of metastatic neuroblastoma in the craniofacial bone in children
Xin BIAN ; Zhenchang WANG ; Junfang XIAN ; Mei LI ; Fei YAN ; Qinghua CHEN ; Bentao YANG ; Qinglin CHANG ; Qichang TIAN ; Zhonglin LIU
Chinese Journal of Radiology 2009;43(3):258-261
Objective To investigate the characteristic imaging findings of metastatic neuroblastoma in the craniofacial bone in children. Methods Imaging findings in 12 patients with metastatic neuroblastoma in the craniofacial bone were analyzed retrospectively. Among them, 10 patients underwent plain CT scan, 6 underwent MRI and 7 underwent whole body single-photon emission computed tomography bone scanning.Results In the 10 patients with CT images, lytic bone destruction and soft tissue masses were found in 9 cases, in which periosteal reaction was observed in 8 patients with spiculated periosteal reaction in 3 patients.The remaining 1 patient didn't show any abnormalities on CT images but had abnormal findings in bone scanning.Six patients with MR images showed abnormal signal intensity in the bone marrow of the craniofacial bone and adjacent soft tissue masses. Postcontrast T1-weighted imaging in 5 patients demonstrated remarkable enhancement of the bone marrow and soft tissue masses. Bone scanning of 7 patients showed abnormal foci of increased radionuclide activity of the craniofacial bone in 7 patients and metastasis at other body parts in 6 patients.Conclusion The metastatic neuroblastoma in the craniofacial bone has its characteristic imaging findings which are helpful for correct diagnosis.
3.Three-Dimensional Foot Shape Modelling Based on Statistical Shape Model
Qichang MEI ; Zixiang GAO ; FERNANDEZ JUSTIN ; Yaodong GU
Journal of Medical Biomechanics 2021;36(1):E096-E101
Objective To establish the three-dimensional (3D) statistical shape model (SSM) of the foot, so as to reveal the 3D foot shape variations. Methods Foot data from 50 normal Chinese young males were used for 3D statistical shape modelling. Steps, including mesh registration of foot surface, axis alignment and principal component (PC) analysis (dimension reduction), were performed to obtain the parameterized foot shape (mean shape and standard deviation of PC). Results Through the principal component analysis (PCA), the 3D foot shape varied in the length and width (PC1, 48.01%), arch and dorsal height (PC2, 11.38%), and hallux abduction-adduction position (PC3, 7.48%). Conclusions Based on the parameterised 3D foot SSM, these datasets can be applied into the population-based shoe last manufacture, orthotics customization and quick diagnosis of foot disorders in clinic.
4.Progress on Biomechanical Research of Image-Based Subject-Specific OpenSim Lower Extremity Musculoskeletal Model
Qichang MEI ; Yaodong GU ; Dong SUN ; Jianshe LI ; FERNANDEZ JUSTIN
Journal of Medical Biomechanics 2020;35(2):E259-E264
OpenSim musculoskeletal modelling has developed rapidly and been widely utilized due to its open-source. Apart from calculation of the basic kinematic and kinetic data, subject-specific OpenSim model could reveal information of neuromuscular control, muscle forces and geometry, and contact forces. Image-based model-ling of the neuromuscular control in pathological gait and ergonomic evaluation of the prostheses confirmed the reliability and feasibility, but limitations in time-consumption and foot-ankle modelling also existed. The subject-specific modelling of pathological gait could improve the accuracy and diversity of clinical biomechanics and medical engineering research. It could also reveal the pathological features, and provide scientific evidence to design specific and accurate protocols of motor function diagnosis and rehabilitation, health monitoring and evaluation, and ergonomic customization and assessment of devices, as well as future directions and implications in the research field.
5.Analysis of Ground Reaction Forces during Running Based on One-Dimensional Statistical Parametric Mapping
Qichang MEI ; Liangliang XIANG ; Jianshe LI ; FERNANDE JUSTIN ; Yaodong GU
Journal of Medical Biomechanics 2021;36(5):E684-E691
Objective To analyze the difference in ground reaction force (GRF) between male and female runners and between left and right limbs using the one-dimensional statistical parametric mapping (SPM). Methods Thirty male and female runners participated the running test on force treadmill at the speed of 12 km/h. GRF of consecutive five steps were recorded. The independent-sample t test and paired-sample t test in the SPM package were used to check the male vs female and right limb vs left limb differences. Results Male and female runners showed inter-limb asymmetry in vertical average loading rate (VALR), and the VALR of male runners was significantly higher than that of female runners in the left limb, while no significant differences were found in the right limb. Male and female runners showed significant differences in the right vertical GRF during push-off and medial-lateral GRF during landing, while left medial-lateral GRF presented significant differences during landing and mid stance. Male runners showed right limb vs left limb significance in the anterior-posterior GRF during push-off, vertical GRF during landing and push-off and medial-lateral GRF during landing, while female runners exhibited right limb vs left limb significance in vertical GRF during landing and push-off. Conclusions This study introduced the application of SPM in statistical analysis of GRF, elaborated the procedures and theory, compared the test of time-series data in SPM and discrete value with traditional statistics, and discussed the difference and features in SPM and SnPM, thus providing references for the application in data analysis of sports biomechanics. Comparison in the male vs female and right limb vs left limb revealed the genders and inter-limb symmetrical differences in the landing, mid-stance and push-off phases during stance. The research findings laid the foundation for future investigation of mechanism in running related injuries and strategy of prevention and treatment.