3D reconstruction from medical images is widely used in diagnose, radiotherapy surgery programming and medical research. This paper deals with the framework and key techniques of 3D reconstruction system of medical images. Methods of automatic and manual segmentation of medical images are designed. Data structure of the system is proposed. The system data are encapsulated in object-oriented paradigm and the hierarchical structure of classes is presented for reconstructing 3D geometry models. The 3D surface geometry model is constructed by using MT algorithm from the tissues extracted by automatic or manual segmentation. An edge collapse algorithm of mesh simplification is proposed and implemented, and the surface model constructed by MT algorithm is simplified by using this algorithm, After reduction of 90 percent triangles, the simplified model still maintains the original feature. It can speed up surface rendering of the models.
Algorithms ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional

OBJECTIVE: To compare the hemostatic efficacy and safety of endoscopic band ligation(EBL) and endoscopic hemoclip placement(EHP) for bleeding due to Dieulafoy lesions in the upper gastrointestinal tract. METHODS: Between February 2004 and October 2006, 34 patients with Dieulafoy lesions in the upper gastrointestinal tract were prospectively enrolled,including 22 cases of lesions in the stomach,10 in gastrointestinal stoma,and 2 in duodenal, who were randomly assigned to undergo EBL (n=16) or EHP (n=18). The therapeutic results of these 2 groups were compared. RESULTS: The median number of O-ring or hemoclip required in the EBL group and the EHP group was similar. The rate of primary haemostasis,recurrent bleeding,transfer into surgery, complications, and average stay and blood transfusion requirements did not significantly differ in the 2 groups (P>0.05). CONCLUSION In this study, no significant differences are detected in the efficacy and the safety of EBL vs. EHP for bleeding due to Dieulafoy lesions in the upper gastrointestinal tract.
Adult ; Aged ; Endoscopy, Gastrointestinal ; methods ; Female ; Gastric Mucosa ; surgery ; Gastrointestinal Hemorrhage ; surgery ; Hemostasis, Endoscopic ; methods ; Humans ; Ligation ; methods ; Male ; Middle Aged ; Prospective Studies ; Surgical Instruments

OBJECTIVE: To assess the safety and efficacy of carbon dioxide (CO(2)) in colonoscopy examination. METHODS: We randomized 349 patients to undergo colonoscopy with insufflation of air (n=175) or CO(2) (n=174). At colonoscopy, p (ET CO(2)) was observed at 4 time points: before the exam, arrived caecum, back rectum, and after the exam. Patient's experience of pain in the end and after the examination at 1, 3, 6, and 24 h was registered using a visual analog scale (VAS). Sedation was not used routinely. RESULTS: The groups were similar in age, sex, inspection time, and caecal intubation rate (all P>0.05). There were no significant differences in p (ET CO(2)) values between the 2 groups before and after the procedure (all P>0.05). VAS scores in the CO(2) group at various time points after the examination were significantly lower than those in the air group (all P<0.05). The percent of VAS scores of 0 in the CO(2) group after 1, 3, 6, and 24 h was significantly higher than that in the air group (all P<0.01). CONCLUSION Injection of CO(2) for colonoscopy will not cause CO(2) retention, and it may significantly reduce the pain, which is safe and effective.
Abdominal Pain ; prevention & control ; Adult ; Blood Gas Monitoring, Transcutaneous ; Carbon Dioxide ; Colonoscopy ; adverse effects ; methods ; Female ; Humans ; Male ; Middle Aged ; Safety

Humans ; Cardiologists ; Neoplasms/drug therapy* ; Medical Oncology ; Heart ; Oncologists