Reproducible Abnormalities and Diagnostic Generalizability of White Matter in Alzheimer's Disease / 神经科学通报·英文版

Alzheimer's disease (AD) is associated with the impairment of white matter (WM) tracts. The current study aimed to verify the utility of WM as the neuroimaging marker of AD with multisite diffusion tensor imaging datasets [321 patients with AD, 265 patients with mild cognitive impairment (MCI), 279 normal controls (NC)], a unified pipeline, and independent site cross-validation. Automated fiber quantification was used to extract diffusion profiles along tracts. Random-effects meta-analyses showed a reproducible degeneration pattern in which fractional anisotropy significantly decreased in the AD and MCI groups compared with NC. Machine learning models using tract-based features showed good generalizability among independent site cross-validation. The diffusion metrics of the altered regions and the AD probability predicted by the models were highly correlated with cognitive ability in the AD and MCI groups. We highlighted the reproducibility and generalizability of the degeneration pattern of WM tracts in AD.

Preliminary application of 3D printing in vitro guide plate assisted deformity correction in child genu varus or valgum / 重庆医学

Objective To research and prepare the individualized knee in vitro guided plate by 3D printing technique and to investigate the feasibility of its application in 8-plate epiphysiodesis.Methods Twelve children patients with knee varus or valgum in our hospital from January 2014 and November 2016,7 boys and 5 girls,average age of 8.2 years old,were performed the lower extremity continuous spiral CT scanning in the knee straight position.The Dicom format stored CT data were imported into software Mimics 15.0 for reconstructing the knee joint 3D model.The knee joint data after reconstruction were guided into software Geomagic1 1.0 with the.stl format.According to the demand that screws without perforating epiphyseal and joint surface,paralle ling to the epiphyseal and locating in the anterior-posterior median line of epiphyseal,the 8-plate placing screw navigation template was designed and printed by using the 3D printing technique;the 8-plate plate and screw internal fixation was conducted by intraoperative template location.The placed screw position was evaluated by postoperative CT.Results The imaging identification showed that 8-plate epiphysiodesis by using 3D printing individualized in vitro guided plate had accurate screw placement.The cases were followed from 6 months to 2 years,the satisfactory orthopedic effect was obtained in all cases.Conclusion Preparing the individualized knee in vitro guided plate by applying 3D printing technique in assisted 8-plate epiphysiodesis for treating child knee varus or valgum has accurate screw position and satisfactory effect.