Research Of 3D Reconstruction And Display Techniques For Ultrasonic Images

The technique of three-dimensional (3D) reconstruction from medical ultrasonic images plays an important role in modern clinical application. The 3D structure of the tissue can be realistically displayed on computer CRT by 3D ultrasonic reconstruction system, which processes traditional two-dimensional (2D) ultrasonic images. Via man-machine interaction, the doctor can manipulate the 3D structure freely such as rotating, zooming out, zooming in, etc. It provides clinical doctors spatial distribution of diseased part and its surroundings in a more comprehensive way, so as to help them make exact clinical diagnosis.In this paper, with an overview of the key problems and development of 3D ultrasonic imaging, the demands and technique feasibility of 3D reconstruction from medical images have been investigated. Based on the summary of former achievements and analysis of application requirements, the methods and algorithms for 3D reconstruction from ultrasonic images of human liver veins are proposed.The algorithms for B-type ultrasonic image processing, including preprocessing and segmentation, have been studied. The noise reduction and image enhancement algorithms are discussed, with consideration of ultrasonic image characteristics, such as speckle noise existence, lower grade and contrast. Based on the Otsu method, a modified algorithm for 3D ultrasonic image segmentation is proposed and the experiment results are satisfactory.Much more attention has been paid to the technique of surface reconstruction from a series of parallel planar contours, which are extracted from a 2D ultrasonic image sequence. Under the guideline of contour matching, an improved solution is achieved by using a new contour-matching method to solve the problems in reconstruction of single contour lines and multi-contour lines. 3D realistic display of reconstructed human liver veins is implemented by using OpenGL programming. The system structure, functional modules and software flow are also briefly described.Finally, a conclusion of this paper is presented, followed by some suggestions on further research work.