MRI Moving Ghost Cancellation And Image Enhancement Method

MRI is vulnerable to be affected by motion and ghost will appear in the image. Especially, ghost tends to appear in low magnetic field MRI system. This paper intends to deduce an automatic post processing method to deal with the ghost image. It includes method of ghost cancellation and image enhancement in MRI.We use snake algorithm to find the object's edge, at the same time, adjust the ghost cancellation algorithm, and divide the process into two steps. First, cancel ghost roughly in order to get the exact ROI (region of interesting); second, use the right ROI to cancel the ghost precisely. The main job in ghost cancellation in this paper is to get an auto method which can find the precise ROI and to achieve an image without ghost.Some information of the image is lost during the data sampling due to the motion, the quality of the image treated by the post processing algorithm degrades, and it is necessary to enhance the image. Detail is abundant in MRI image and the trifle difference in the gray scale denotes different structure. To maintain this difference in image enhancement, this paper use wavelet transform algorithm to divide the ghost cancelled picture into two part, one part include the edge, and the other contain the non-edge information. At the same time fuzzyset enhancement algorithm is used to enhance two parts of picture with difference parameters.The mended method exclude image expert to join in ghost cancellation work, but the auto method can achieve the image which quality is as good as the image quality that the method including image expert achieve. After enhanced, detail of the image is more clearly and the image is as good as the ideal image. It is proved effective by experiment.