The registration of preoperative magnetic resonance (MR) images and intraoperative ultrasound (US) images is very important in the planning of brain tumor surgery and during surgery. Considering that the two-modality images have different intensity range and resolution, and the US images are degraded by lots of speckle noises, a self-similarity context (SSC) descriptor based on local neighborhood information was adopted to define the similarity measure. The ultrasound images were considered as the reference, the corners were extracted as the key points using three-dimensional differential operators, and the dense displacement sampling discrete optimization algorithm was adopted for registration. The whole registration process was divided into two stages including the affine registration and the elastic registration. In the affine registration stage, the image was decomposed using multi-resolution scheme, and in the elastic registration stage, the displacement vectors of key points were regularized using the minimum convolution and mean field reasoning strategies. The registration experiment was performed on the preoperative MR images and intraoperative US images of 22 patients. The overall error after affine registration was (1.57 ± 0.30) mm, and the average computation time of each pair of images was only 1.36 s; while the overall error after elastic registration was further reduced to (1.40 ± 0.28) mm, and the average registration time was 1.53 s. The experimental results show that the proposed method has prominent registration accuracy and high computational efficiency.
In recent years, transesophageal echocardiography has a trend toward miniaturization, so it has great clinical significance and broad clinical application prospect in the management of Cardiac Surgery ICU patient. This paper presents the characteristics of miniaturized transesophageal echocardiography and its clinical application. And we also focused on the contrast between miniaturized transesophageal echocardiography and standard transesophageal echocardiography and transthoracic echocardiography.
Deep hypothermic circulatory arrest (DHCA) is an important assistant technique for complex cardiac surgery, which creates convenient operating conditions for surgery, and is also one of the measures to protect the brain during operation. However, the complications caused by this technique cannot be ignored, and it should be noticed that the occurrence of intestinal injury is relatively insidious, but brings great pain to patients and significantly reduces the quality of life after operation. Studies have shown that intestinal ischemia-reperfusion injury is induced by DHCA. It causes mast cells to activate and release many inflammatory mediators that destroy the intestinal mucosal epithelium barrier, and eventually lead to intestinal injury. This article reviewed the research progress of mast cells in the mechanism of DHCA-induced intestinal injury.
This study aims to determine the salient brain regions with abnormal changes in white matter structures from diffusion tensor imaging (DTI) images of the patients with temporal lobe epilepsy (TLE), and to discriminate the patients with TLE from normal controls (NCs). Firstly, the DTI images from 50 subjects (28 NCs and 22 TLE) were acquired. Secondly, the four measures including the fractional anisotropy (FA), the mean diffusivity (MD), the axial diffusivity (AD) and the radial diffusivity (RD) were calculated. Thirdly, the tract-based spatial statistics (TBSS) was adopted to extract the measures in brain regions with significant differences between the two compared groups. Fourthly, the obtained measures were used as input features of the support vector machine (SVM) for classification, and the support vector machine-recursive feature elimination (SVM-RFE) was compared with the support vector machine-tract-based spatial statistics (SVM-TBSS) method. Finally, the essential brain regions and their spatial distribution were analyzed and discussed. The experimental results showed that the FA measures of the TLE group decreased significantly in the corpus callosum, superior longitudinal fasciculus, corona radiata, external capsule, internal capsule, inferior fronto-occipital fasciculus, fasciculus uncinatus and sagittal stratum, which were nearly bilaterally distributed, while the MD and RD increased significantly in most of these brain regions of the TLE group. Although the AD also increased, the differences were not statistically significant. The SVM-TBSS classifier obtained accuracies of 82%, 76% and 76% using the FA, MD and RD for classification, respectively, and 80% using combined measures. The SVM-RFE classifier obtained accuracies of 90%, 90% and 92% using the FA, MD and RD respectively, while the highest accuracy was 100% using combined measures. These results demonstrated that the SVM-RFE outperformed the SVM-TBSS, and the dominant characteristic influencing classification in brain regions were in associative and commissural fibers. These results illustrated that the measures of DTI images could reveal the abnormal changes in white matter structure of patients with TLE, providing effective information to clarify its pathological mechanism, localize the focus and diagnose automatically.
Objective To investigate the risk factors of prolonged postoperative mechanical ventilation for adult patients with atrioventricular septal defect (AVSD). Methods We retrospectively analyzed the clinical data of 76 patients with AVSD aged more than 18 years in our hospital from January 1, 2011 to December 31, 2017. The patients ventilated longer than 24 hours were described as a prolonged ventilation group (n=27) and the others as a normal group (n=49). There were 9 males and 18 females aged 32.22±9.64 years in the prolonged ventilation group, and 16 males and 33 females aged 35.98±11.34 years in the normal group. Perioperative variables between the two groups were compared and selected, and then analyzed by logistic regression analysis. Results The result of univariate analysis showed that there was a statistical difference in weight, preoperative pulmonary artery systolic pressure, duration of cardiopulmonary bypass, the level of postoperative platelet, hemoglobin, blood glucose, lactic acid and serum creatinine, postoperative maximum heart rate and postoperative infection rate between the prolonged ventilated group and the normal group. Multivarable logistic regression showed that preoperative pulmonary artery hypertension (OR=1.056, 95%CI 1.005 to 1.110, P=0.030), prolonged duration of cardiopulmonary bypass (OR=1.036, 95%CI 1.007 to 1.066, P=0.016) and the low postoperative hemoglobin level (OR=0.874, 95%CI 0.786 to 0.973, P=0.014) were the risk factors of prolonged postoperative mechanical ventilation. Conclusion Preoperative pulmonary artery hypertension, long duration of cardiopulmonary bypass and postoperative anaemia are the risk factors associated with prolonged postoperative mechanical ventilation.