Three-D Visualization Study On Flap Based On The Operational Platform Of Personal Computer

Study backgroundAnatomic studies on vascular system of the skin flap in the field of microsurgery have carried out widely, for example, the success of multilayer CT(MSCTA) in the clinic application, provide us a new method and developing vacuity. Aiming at non-harm and strong direct-viewing multilayer CT, successful experiences have been made from the view of heart and cerebrovascular lesion and vertebral canal morphology. At the same time, these studies have given us some imaging techniques and means on the research of skin flap blood vessel morphology, additionally, with the unceasing development of computer processing tech, re-establishment of skin flap 3D dissect coming to be possible. This study established a foundation for observation on the state of skin flap blood supply stereoscopically and making best operative route and treatment plan, implementing the development from plane anatomy to stereoscopic and digital anatomy.Now, on the clinic, the design of skin flap mainly relies on the doctors experiences. The definition of the position, magnitude, geometry of the skin flap and the spatial relation of skin flap and peripheral vascular tissue can not be analyzed quantitatively exactly. The development of modern skin flap chirurgery needs badly the three- dimension picture system to display the blood supply and other profound structures and functions. This kind of system can also support the clinical training, designing of operative route, suppositional operation procedure and fidelity navigation during the operation. 3D imaging studies such as computed tomography (CT) and magnetic resonance (MR) provide the primary source of patient-specific data for such medical applications. The two-dimensional (2D) images produced by CT and MR imaging techniques represent a series of cross-sectional image slices through one's anatomy. When stacked on top of each other, these images represent the 3D structure of the one's anatomy. Two methods for reconstructing the 3D volume from the 2D images are surface rendering) and volume rendering. Surface rendering requires that the medical data be segmented, and that a geometric surface representation of the structures of interest be extracted. The advantage of this technique lies in the relatively small amount of contour data, resulting in fast rendering speeds. Shaded surface displays are useful if there is a need or desire to visualize specific 3D surfaces. Shaded surface displays are a 2D representation of a 3D surface. Volume rendering, by contrast, enables the visualization of 3D data without fitting geometric primitives to the data, but volume image data sets are characteristically large, taxing the computation abilities of volume-rendering techniques and the systems on which they are implemented. Of the methods available, SSD has been the most commonly used 3D technique, because it requires a small amount of data and can therefore be implemented on less powerful computers. This is why we chose SSD to display the outline of ALT flap and ADP flap. Our 3D reconstruction models perfectly displayed their anatomical characteristics. These models can be used in surgical simulation and medical training.In the departed medical visualization techniques systems, expensive expert graphicWorkstations, super computers with more CPU or calculating distrubutedly are needed. It is a future trend that 3D image processing of the skin flap on PC. The main characteristics of PC image processing is that it can meet the need of general engineering application at a rather low price. And luckily, the manufactures of the software have transplanted main stream application software to the PC partly or totally. Accordingly, in this study, the 2D or 3D analyzes on the skin flap artery by use of PC and single rebuilding software. For example, the divisional extraction of the area-of-interest and 3D visualization, have come to satisfactory results, which can help the doctor make qualitative and quantitive analyses on the structure of skin flap and other area-of-interest.Objectives1. Three-dimensional computerized reconstructions of flap were conducted from these data by means of continuous thin-layer CTA2.To observe the normal structure of flap artery in one adult fresh cadaver specimens perfused with lead oxide-gelatine mixture and to establish their digitized visible models.3.The 3D models can providing morphologic data for clinical training, pre-operation designing and virtual reality operation procedure.Materials and methods1.The personal computer system ofthree-D visualization study: Platform: Intel CoreTM Duo processor T2050 (2 MB L2 cache, 1.6 GHz, 667MHz FSB); System memory: Up to 1GB of DDR2 533 MHz memory; Storage: 120 GB SATAJ100 hard disk drive; NVIDIA GeForce Go 7300 graphics with 128 MB of dedicated GDDR2 VRAM, supporting NVIDIA PowerMizer 6.0; 15.4" WXGA 200-nit Acer CrystalBriteTM highgraphics brightness TFT LCD, 1280 x 800 pixel resolution, 16 ms response time, supporting simultaneous multiwindow viewing via Acer GridVistaTM; Operating system Genuine Windows XP Home Edition (Service Pack 2); software:Photoshop7.0,Geomagic Studio 5.0和RapidForm2004; the platform of three-D visualization study: Amira4.1.2.Three-D visualization study on continuous thin-layer CTA: Five healthy adult (two men) underwent bilateral examination with thin-layer imager (philips 64CT) to assess the flap structures of the extremitas inferior in Zhujiang Hospital, Southern Medical University. They were subject to radiographic CT volume scanning. Extent was from abdominal aorta to toes. The date were tube tension 120 kV, tube current 250～300 mA, pachy 1mm×64, rapid 47.5 mm/circle, pitch 0.891, image reconstruction 1mm, 0.5mmo constrast medium 3.5～4.0ml/s, working station "Brilliance"3.Three-D visualization study on CT section of the cadaver specimen: One man adult fresh cadaver specimen was perfused with lead oxide-gelatine mixture to be subject to radiographic CT scanning, scans covering both lower limbs with 1.0 mm collimation (120 kV, 110 mA, pitch 2mm, 512×512 matrix). The 2D images in Dicom format were correlated to the 3D models of the entire region by means of Amira software along with the cross-sectional images into standardized views. The segmented areas for skin, flap structures were displayed in different colors using tools of Brush, Lasso and Magic wand. Segmentation is performed using a custom-written discrete snake procedure. The 3D reconstruction via the Amira 4.1 software consisted of tracing the contours of the anatomical structures to be reconstructed; adjustment by geometrical alignment of the contours of stacked points; modeling of the surfaces by meshing the framework of the points transformed into polygons (wire-framed object) and smoothing the contours of the object reconstructed from points (surface rendering) . 3D models of these structures were saved as STL format, and then input Imageware 9.0 software to be re-touching and re-dividing.Results1.Three-D visualization study on continuous thin-layer CTA: The technique of continuous thin-layer CTA of limbs provided new way to clinicist who could get the message of variation and pathological changes. They identified that patients need free flap transplantation whether or not. They could get more 3D information than common blood vessel blood vessel. The source and trip of flap could be chased by means of three-D visualization. The length of blood vessel and diameter could be elected in operation. Because the leptos caliber could not be dev, three-D visualization was below the mark. Personal computer had affluent hand-motion tool, automatic and reciprocation extraction of diremption and extraction. Three-D visualization was very superiority.2.Three-D visualization study on CT section of the cadaver specimen: The 3D images could display perfectly the main structures of flap and other adjacent structures by means of personal computer and software Amira4.1. Correlation of cross-sectional images from CT-scanning to 3D models is a more effective way of understanding of the flap anatomy. 3D reconstructed models of flap can be applied in clinical training, pre-operative designing and virtual operation procedures And also we transformed the images into movies with distinct and fluent frames by means of movie maker software. Conclusions1.Muti-silce helical CTA can display part of morphologic data of blood vessel. Three-D reconstruction can elevate observation of blood vessel and operative design of surgical flap for clinician2.The cross-section anatomy of the normal structure of flap artery in one adult fresh cadaver specimens perfused with lead oxide-gelatine mixture can be observed. Their digitized visible models can provide upstanding morphologic evidence.3.Three-D Visualization study on flap based on the operational platform of personal computer. It can provide the platform of the individual personality to clinicist.