Rapid image registration for extended-field-of-view ultrasound

Extended fleld-of-view (EFOV) can acquire a full field of vision, which can help doctors to make more objective and accurate diagnosis. Current EFOV techniques suffer from the low computation speed due to the large amount of ultrasound data of image blocks to be registered. This paper describes a novel technique to register 2D ultrasound images and form EFOV images with significantly reduced computation time by using a less number of image frames. With an assumption that the moving direction and speed for the probe are nearly identical during the data collection, we are able to estimate the moving speed of the probe by registering the frames one by one at the beginning of data collection for roughly determining the frame interval for the whole image sequence. Using the estimated frame interval, a smaller number of frames can be selected. The overlapping area and searching range for the registration of the selected frames can be pre-determined. To further improve the computational efficiency and robustness of the registration, we innovatively propose to select fewer blocks which are regarded as the most valid blocks based on the importance of image content in each block. The experimental results show that our method can produce as good expanded images as the traditional method does. Moreover, the computation time is significantly reduced.