Non-rigid medical image registration is a popular subject in the research areas of the medical image and has an important clinical value. In this paper we put forward an improved algorithm of Demons, together with the conservation of gray model and local structure tensor conservation model, to construct a new energy function processing multi-modal registration problem. We then applied the L-BFGS algorithm to optimize the energy function and solve complex three-dimensional data optimization problem. And finally we used the multi-scale hierarchical refinement ideas to solve large deformation registration. The experimental results showed that the proposed algorithm for large deformation and multi-modal three-dimensional medical image registration had good effects.
ObjectiveTo evaluate the association between H2RA and the risk of hip fracture by performing a meta-analysis. MethodsWe searched CNKI, PubMed and EMbase from inception to September 19th 2016, to collect case-control studies or cohort studies reporting the risk of hip fracture with H2RA. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then meta-analysis was performed using Stata 13 software. ResultsEleven studies involving 206 276 hip fracture cases were included. The result of meta-analysis showed that patients receiving H2RA therapy had approximately 1.12 times the risk of developing hip fracture compared with nonusers (OR=1.12 95%CI 1.02 to 1.24, P=0.022). Subgroup analyses by interval time indicated that the risk appeared greater with the continuous users (OR=1.11, 95%CI 1.01 to 1.24, P=0.039) whereas the discontinuous users was not significantly associated with hip fracture risk. ConclusionH2RA therapy may be associated with an increased risk of hip fracture. For patients with intermittent medication, the side effect may disappear by discontinuation of PPI use for at least 30 days, but the study did not find time-effect relationship or dose-effect relationship. Considering the limitations of this study, more rigorous clinical trials evaluating the potential side-effect of H2RA are needed.