Segmental meshing of brain tissues and simulation of soft tissue deformation / 南方医科大学学报

Virtual surgery provides important assistance in preoperative planning of brain surgeries. A virtual surgery system essentially consists of visualization and modeling of the medical data and deformation simulation of human organs (mainly soft tissues). We used the hybrid level set theory, threshold segmentation, and morphological methods to segment the human head MRI volumetric data into five parts, namely the outline of the head, gray matter, white matter, cerebrospinal fluid and ventricles. The iso2mesh toolkit based on Delaunay algorithm was then employed to generate the tetrahedral mesh and mark the five parts. We further studied the soft tissue deformation, and established a mechanic model based on Tensor-Mass system to simulate the point-touch and ball-touch models for soft tissue deformation. This approach can help to improve the positioning accuracy of a virtual brain surgery and represent the process of brain tissue deformation.

Clinical value of wireless capsule endoscopy in diagnosis of small bowel disease in children / 中华儿科杂志

<p><b>OBJECTIVE</b>The pathological change of small bowel is difficult to examine because it is anatomically unique. The development of wireless capsule endoscopy provides an unique opportunity to visualize the entire small bowel in a minimally invasive manner. The aim of this study was to assess the safety and clinical value of wireless capsule endoscopy in children.</p><p><b>METHODS</b>During the last 4 years (June, 2004-June, 2008), 46 times of wireless capsule endoscopy were performed in 43 patients with suspected small bowel disease, including obscure gastrointestinal bleeding (n = 11), recurrent abdominal pain (n = 20), chronic diarrhea (n = 9), protein losing enteropathy (n = 2), recurrent vomiting (n = 1). Of the 43 cases, 28 were male and 15 were female, the age ranged from 6 to 18 years, 8 of these cases were < 10 years old. The weight of the patients ranged between 15 kg and 60 kg. The average time of capsule passing through the stomach and the small intestine, the tolerance to and complication of wireless capsule endoscopy in patients, the image quality of capsule endoscopy, and the cleanliness of small intestine after fasting for 8 hours were observed and recorded.</p><p><b>RESULT</b>All the patients could easily swallow the capsule and had good tolerance. The overall success rate was 94% (43/46). The median time of capsule passing through the stomach and small intestine was 73 min (range, 3 - 600 min) and 246 min (range, 73 - 413 min), respectively. The diagnostic yield of pathological change in small intestine was 90% (37/41), and the diagnostic accordance rate was 84% (31/37). Based on the wireless capsule endoscopy, diagnostic findings included Crohn's diseases (15), lymph follicular hyperplasia (4), nonspecific enteritis (4), vascular malformations (3), small bowel tumour (2), primary intestinal lymphangiectasia (2), gastrointestinal motility disorders (2), Meckel's diverticulum (1), angioma (1), small intestinal worm disease (1), duodenal ulcer (1), and polyposis syndromes (1). The capsule of 1 patient remained in the stomach. The cleanliness of small intestine after 8 hours fasting was good. And the capsule endoscopy can show high quality small intestine image.</p><p><b>CONCLUSION</b>Wireless capsule endoscopy is a noninvasive, safe and useful tool for the investigation of the small intestine in children, especially for obscure gastrointestinal bleeding and Crohn's disease.</p>

Design of a volume-rendering toolkit using GPU-based ray-casting / 中国医疗器械杂志

This paper presents an approach to GPU-based ray-casting of a shader model 3.0 compatible graphics card. In addition, a software toolkit is designed using the proposed algorithm to make the full benefit of GPU by extending VTK. Experimental results suggest that remarkable speedups are observed using GPU-based algorithm, and high-quality renderings can be achieved at interactive framerates above 60 fps. The toolkit designed provides a high level of usability and extendibility.

Effect of small bowel preparation with simethicone on capsule endoscopy / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>BACKGROUND</b>Capsule endoscopy is a novel non-invasive method for visualization of the entire small bowel. The diagnostic yield of capsule endoscopy depends on the quality of visualization of the small bowel mucosa and its complete passage through the small bowel. To date, there is no standardized protocol for bowel preparation before capsule endoscopy. The addition of simethicone in the bowel preparation for the purpose of reducing air bubbles in the intestinal lumen had only been studied by a few investigators.</p><p><b>METHODS</b>Sixty-four participants were randomly divided into two groups to receive a bowel preparation of polyethylene glycol (PEG) solution (Group 1) and both PEG solution and simethicone (Group 2). The PEG solution and simethicone were taken the night before and 20 min prior to capsule endoscopy, respectively. Frames taken in the small intestine were examined and scored for luminal bubbles by two professional capsule endoscopists. Gastric emptying time and small bowel transit time were also recorded.</p><p><b>RESULTS</b>Simethicone significantly reduced luminal bubbles both in the proximal and distal small intestines. The mean time proportions with slight bubbles in the proximal and distal intestines in Group 2 were 97.1% and 99.0%, respectively, compared with 67.2% (P<0.001) and 68.8% (P<0.001) in Group 1. Simethicone had no effect on mean gastric emptying time, 32.08 min in Group 2 compared with 30.88 min in Group 1 (P=0.868), but it did increase mean small intestinal transit time from 227.28 to 281.84 min (P=0.003).</p><p><b>CONCLUSION</b>Bowel preparation with both PEG and simethicone significantly reduced bubbles in the intestinal lumen and improved the visualization of the small bowel by capsule endoscopy without any side effects observed.</p>

OMOM capsule endoscopy in diagnosis of small bowel disease / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To assess the diagnostic efficiency of OMOM capsule endoscopy (CE) in a group of patients with different indications.</p><p><b>METHODS</b>Data from 89 consecutive patients (49 males, 40 females) with suspected small bowel disease who underwent OMOM CE (Jinshan Science and Technology Company, Chongqing, China) examination were obtained by retrospective review. The patients' indications of the disease consisted of the following: obscure gastrointestinal bleeding (OGIB), abdominal pain or diarrhea, partial intestinal obstruction, suspected inflammatory bowel disease, tumor of unknown origin, hypoproteinemia, constipation, weight loss, and elevated tumor markers.</p><p><b>RESULTS</b>CE failed in one patient. Visualization of the entire small bowel was achieved in 75.0%. Capsules were naturally excreted by all patients. The detection rate of abnormalities was 70.5% for patients with suspected small bowel disease, and the diagnostic yield for patients with OGIB was higher than that for patients with abdominal pain or diarrhea (85.7% vs 53.3%, P<0.005). Angiodysplasia was the most common small bowel finding. Active bleeding sites were noted in the small intestine in 11 cases.</p><p><b>CONCLUSION</b>OMOM CE is a useful diagnostic tool for the diagnosis of variably suspected small bowel disease, whose diagnostic efficiency is similar to that of the Pillcam SB (small bowel) CE (Given Imaging, Yoqneam, Israel).</p>

Clinical value of capsule endoscopy in obscure gastrointestinal bleeding / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate clinical diagnostic value of capsule endoscopy in obscure gastrointestinal bleeding.</p><p><b>METHODS</b>Capsule endoscopy were performed in 90 patients with obscure gastrointestinal bleeding, which was defined as negative finding by gastroscopy and colonoscopy in our hospital.</p><p><b>RESULT</b>In 90 patients, 2 of them accepted second examination. Eighty-seven of 92 (94.57%) patients accepted of capsule endoscopy successfully including 21 of 25 (84.0%) in group of acute massive bleeding and 66 of 67 (98.51%) in recurrent melena (P <0.05). In above patients, 74 of 87 (85.06%) had positive findings and the false negative rate was 17.24%. The detectable rate in acute massive bleeding and recurrent melena was 80.95% and 86.36%, respectively (P >0.05), and the false negative rate of that was 23.81% and 15.15%, respectively (P >0.05).</p><p><b>CONCLUSION</b>Capsule endoscopy can be performed safely and well-toleratedly for visualizing the small bowel in patients with obscure gastrointestinal bleeding, which induces a highly detectable rate compared with other methods for detecting obscure gastrointestinal bleeding.</p>

The expression and significance of human macrophage metalloelastase in both gastric cancer cell lines and gastric cancer tissues / 中华消化杂志

Objective To investigate the expression of human macrophage metalloelastase(HME) both in gastric cancer cell lines and gastric cancer tissues,and to find the role of HME in gastric carcino genesis.Methods Fifty eight patients who were operated in our hospital during April to Aug.2003 were enrolled.The samples taken from cancer,paracancer or normal tissues of these patients and cancer cell lines(MGC-803,SGC-7901,AGS)were detected for HME protein and HME mRNA expressions by Western blot and immunohistochemistry,RT-PCR and fluorescence quantitative PCR,respectively. Results Both HME mRNA and HME protein expressions were found in all three gastric cancer cell lines.The expressions of HME mRNA and HME protein in gastric cancer tissues was increased signifi- cantly compared with that in normal tissues(P0.05).Conclusions The increased HME expression in gastric cancer tissures compared with normal tissue indicate that HME may be a potential tumor marker for gastric cancer.