Three Dimensional Ultrasound Reconstruction On Image-guided Surgery

With the development of image-guided minimally invasive surgery, the demand ofmedical image processing is more and more urgent.Medical ultrasound (US) images hasattracted great attention in the field of medical image-guided and is playing a more and moreimportant role in modern clinical applications.Compared with the traditional2D(two-dimensional) ultrasound imaging system,3D ultrasound reconstruction system hassuch advantages as more realistic display, more convenient interaction, capability ofmeasuring structural parameters and shorten the doctor diagnosed time, thus can help thedoctor make exact clinical diagnosis.3D US is increasingly being introduced in theclinic,especially it can be applied to image guided for our surgical robot during surgery,which can help the doctor observe the current surgery path and various parameters in order toavoid dangerous zone and shorten the time of operation, consequently complete the real senseof minimally invasive surgery.This paper firstly expounds the present situation domestically and abroad and the mainresearch field of three-dimensional ultrasound reconstruction technology. In consideration ofthe low quality and low SNR(Signal to Noise Ratio)of ultrasound images, algorithms forimage enhancement and segmentation are discussed, which lays the basis for3Dreconstruction. And then begin with3D reconstruction system equipments, I demonstrate theprocess of3D reconstruction in detail, which is divided into three parts: collecting US data,reconstructing volume, and visualizing in3D model. The major part of this paper lies instudying the technology of3D US reconstruction and developing visualization software.Obtaining3D volumes with2D US probes is a two-step process. First, a positioningsensor must be attached to the probe; second, a reconstruction of a3D volume can beperformed into a regular voxel grid. Various algorithms which are based on2D images havebeen used for performing3D reconstruction. In order to make3D reconstruction satisfactorilyeffective, this paper introduces the weighted distance of the interpolation algorithm andappropriate improvement of it to get volume data. Finally, the volume rendering of volumedata using VOLVIEW has been realized. We also work out the software design of3D USreconstruction and visualization.The interpolation of3D US reconstruction is very important. The calculated amount of itrequires enormous effort. So the key point is how to shorten the time of it in the premise ofensuring the quality of reconstruction. We realize3D US reconstruction with VTK in manynuclear CPU environment, it can reduce the time of reconstruction, which is beneficial to real time display.The validity of our3D reconstruction and visualization system is verified through severalexperiments．Then this system is used to reconstruct3D model from a series of ultrasoundimages of phantom, chicken kidney and human liver. The result comes out to besatisfactory． Furthermore, the result is compared with that of other reconstructionmethods．Finally, a conclusion of this paper is presented and some suggestions on furtherresearch work are proposed.