Objective To analyze and explore the value of 3 T high resolution magnetic resonance vessel wall imaging for identifying the activity of Takayasu arteritis. Methods Twenty-six consecutive patients with Takayasu arteritis underwent 3.0 T high resolution MR vessel wall imaging on supraortic vessels (according to the classification of Lupi-Herrea , type Ⅰ and Ⅲ were included). Sixteen patients were in active phase and 10 in inactive phase based on the Kerr criteria. The MR vessel wall imaging appearances of Takayasu arteritis were compared between the active phase and inactive phase cases. Results Wall thickening was demonstrated in all involved arteries. There were statistically significant differences between active phase and inactive phase cases in MR appearances including multi-ring thickening of vessel wall (75/80 and 18/50), arterial inner wail enhancement (50/80 and 19/50), obscurity of perivascular fat (55/80 and 18/50,X<'2>=50.39,7.41,13.40,P<0.01). There was also a statistically significant difference in the thickness of carotid artery wall between the two groups [ (3.8±0.2) mm vs (2.5±0.8) mm]. Conclusion 3 T high resolution MR vessel wall imaging is valuable for identifying the activity of Takayasu arteritis.

Objective To assess the safety and the curative effect of the combination of minipercutaneous nephrolithotomy (mini-PCNL) and ureteroscopic lithotripsy (URL) in the treatment of nonhydronephrotic staghorn calculi. Methods The clinical data of 53 eases with non-hydronephrotic staghom calculi treated by mini-PCNL combined with URL were retrospectively analyzed. Results Fifty-three cases (64 renal units) were performed first-stsge operation, 9 renal units were stone free in first-stage operation, 33 renal units were stone free in second-stage operation, other 13 renal units were stone free in third-stage operation. A complete stone clearance rate of 85.9%(55/64) was achieved, and after one to three sessions of mini-PCNL and extracorpereal shock wave lithotripsy afterwards that increased to 95.3% (61/64). Blood transfusion was performed in 3 cases, no major complication was noted in the patients. Conclusions The combination of mini-PCNL and URL has more advantages, less invasions, easier recovery and less complications. It provides a new minimally invasive way for non-hydronephrotic staghorn calculi.

Objective To explore emergency treatment methods for acute renal failure caused by negative imaging ureterolith. Methods There were 36 cases of acute renal failure caused by negative imaging ureterolith, which were finally diagnosed by ureteroscope examination. The negative imaging ureterolith were broken by air pressure ballistic curve shock wave,and taken out of ureter by ureteroscope. All cases were put double-J in ureter. Results Thirty-six cases were got success relieves of ureter obstruction in 24 hours. The urine volume of them were increased, symptoms of urinemia were disappeared, BUN and creatinine were normal after operations. Conclusions The treatment and diagnosis methods by ureteroscope for acute renal failure caused by negative imaging ureterolith are quick and safety, which can treat both side ureterolith at the same time and get reliable and safe effect with less trauma. It should be the first choice to treat acute renal failure caused by negative imaging ureterolith.

The rotation axis equation of the simple articulator is built by the cylinder feature identification, which facilitates the rotation transform of the lower jaw data. Then the collision points and areas on the position of centric occlusion are found to form two collision couples. The virtual orientation of the lower and upper jaws model is realized by collision detection of the collision couples. Consequently the occlusal relation between the lower and upper jaws is established. It sets a good basis for the virtual adjustment of edentulous occlusal surface. The jaw movement of opening and closing in the state of hinge axis is also simulated accordingly.
Computer Simulation ; Computer-Aided Design ; Dental Articulators ; Dental Models ; Dental Occlusion, Centric ; Denture Design ; methods ; Humans ; Jaw ; physiology

Complex surgeries often need multi-disciplinary surgeons to work collaboratively and set synthesized operation plans. Aided by collaboration enabled three dimensional visualization software over network, operation plans can be made more intuitively and accurately. Because different disciplinary surgeons often work at different locations, a distributed collaboration virtue environment over network should be provided. By our knowledge, such a system does not exist yet. Toward this, we implement a platform upon Client/Server architecture over network. The 3D model is reconstructed from CT image data of DICOM format and the resulting mesh is then simplified, using the Visualization Toolkit (VTK). The simplified polygon mesh data is further seamlessly integrated into our 3D graphics system developed with the HOOPS/3DAF for displaying, where the model is converted to the lossless compression stream file format-HSF, which is suited for network transmission. Using this format, a collaboration enabled interactive visualization system is implemented upon Client/Server architecture, developed with HOOPS/NET toolkit. The reconstructed 3D model is clear, and the interactive collaboration with 3D visualization is fairly real-time. We then implemented a platform for developing collaborative surgery simulation software, into which the surgery operation simulation and prosthesis design function can be easily added.
Computer Simulation ; Diagnostic Imaging ; methods ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods ; Internet ; Software ; User-Computer Interface

In order to satisfy the current demand for fast and high-quality prosthodontics, we have carried out a research in the fabrication process of the porcelain fused to metal crown on molar with CAD/CAM technology. Firstly, we get the data of the surface mesh on preparation teeth through a 3D-optical grating measuring system. Then, we reconstruct the 3D-model crown with the computer-aided design software which was developed by ourselves. Finally, with the 3D-model data, we produce a metallic crown on a high-speed CNC carving machine. The result has proved that the metallic crown can match the preparation teeth ideally. The fabrication process is reliable and efficient, and the restoration is precise and steady in quality.
Computer-Aided Design ; Crowns ; Dental Porcelain ; Dental Prosthesis Design ; Humans ; Metal Ceramic Alloys ; Molar

This paper presents our work on the research process of virtual articulator simulation. Firstly, plaster models of upper jaw and low jaw are measured by 3D-optical measuring system and processed to get the available data. Secondly, complex physical modeling of the jaw motion is simplified and decomposed to a series of position transform, such as translation, rotation, etc.. Thirdly, opening/closing movement and laterotrusion is simulated by real-time updating display. Fourthly, the efficient collision detection algorithm is applied to dynamically compute occlusal contact regions and cutaway view. Finally, the current shortage of the virtual articulator simulation is discussed in detail and research prospect is forecasted.
Computer Simulation ; Dental Articulators ; Dental Occlusion ; Humans ; Imaging, Three-Dimensional ; Jaw ; physiology ; Models, Biological

The database with standard 3D tooth crowns has laid the groundwork for dental CAD/CAM system. In this paper, we design the standard tooth crowns in 3DS MAX 9.0 and create a database with these models successfully. Firstly, some key lines are collected from standard tooth pictures. Then we use 3DS MAX 9.0 to design the digital tooth model based on these lines. During the design process, it is important to refer to the standard plaster tooth model. After some tests, the standard tooth models designed with this method are accurate and adaptable; furthermore, it is very easy to perform some operations on the models such as deforming and translating. This method provides a new idea to build the database with standard 3D tooth crowns and a basis for dental CAD/CAM system.
Computer-Aided Design ; Databases, Factual ; Dental Models ; Dental Prosthesis Design ; methods ; trends ; Imaging, Three-Dimensional ; Tooth Crown ; anatomy & histology

This paper presents a new method of designing restoration model of maxillectomy defect through Computer aided technology. Firstly, 3D maxillectomy triangle mesh model is constructed from Helical CT data. Secondly, the triangle mesh model is transformed into initial computer-aided design (CAD) model of maxillectomy through reverse engineering software. Thirdly, the 3D virtual restoration model of maxillary defect is obtained after designing and adjusting the initial CAD model through CAD software according to the patient's practical condition. Therefore, the 3D virtual restoration can be fitted very well with the broken part of maxilla. The exported design data can be manufactured using rapid prototyping technology and foundry technology. Finally, the result proved that this method is effective and feasible.
Computer-Aided Design ; Humans ; Imaging, Three-Dimensional ; Maxilla ; diagnostic imaging ; injuries ; Maxillofacial Prosthesis ; Models, Theoretical ; Prosthesis Design ; Software ; Titanium ; chemistry ; Tomography, Spiral Computed

This paper demonstrates the successful application of a novel approach to the computer aided design (CAD) of removable partial denture (RPD) framework. Firstly, we get the data of the partially edentulous cast, a mandibular Kennedy Class II, through a 3D-optical grating measuring system after corresponding pretreatment. Then, the reverse engineering software and 3D CAD software was used to design basis, big conjunction, clasp, small conjunction of the RPD framework. Finally 3D surface model of the RPD framework was created in preparation for direct manufacture using rapid prototyping (RP) methods and foundry. The result indicated that the RPD framework was fabricated successfully and the resulting frameworks provided a satisfactory fit.
Computer-Aided Design ; Dental Alloys ; Dental Casting Technique ; Dental Prosthesis Design ; methods ; Denture Design ; methods ; Denture, Partial, Removable ; Humans