The study of optical flow in cine MR heart imaging

• Main Authors: Huang, Shiao-Hwa, 黃曉華
• Other Authors: Lin, Mao-Zao; Chen, Jyh-Horng
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/62687032122748184056

碩士 === 國立臺灣大學 === 電機工程研究所 === 84 === We investigate the possibility of using optical flow compu- tation with small neighborhood to describe heart motion. A small and thin elliptical ring image was used in simulation to find suitable computation methods and conditions. The major consideration is about optical flow computation on thin region, infuence of gray scale variation on computa- tion, performance of com-putation on boundaries, and defor- mation effect. Simulation result shows that optical flow computation based on second order derivative and constraint line clustering using 3x3 neighborhood have the best performance. Component median filtering was proved to correctly smooth velocity field, preserve boundary variation, and detail motion. An important improvement on second order derivative method was calculating defferentials based on polynomial interpo- lation, in order to reduce the size of neighborhood involved in computation, show better performance on boundaries and in deformed motion. When extending second order derivative method to three dimentional computation, this improvement also make heart motion computation practical. After applying proper image filtering and registration techniques on cine MR images, smooth two and three dimentional optical flow ve- locity fields were successfully computed. Optical flow graphs show many details of intricate heart motion. Some error ana- lysis was also presented.