| 摘要 |
A phase-sensitive method of inversion recovery MR imaging is provided, which is directed to a specified object. The method comprises the steps of applying an inversion-recovery MR sequence to the object to acquire a set of MR data for an initial image, wherein the initial image comprises a pixel matrix of specified size, each of the initial image pixels having an associated MR signal and a phase vector. The method further comprises generating a phase vector image from information provided by respective initial image pixels, the phase vector image having a matrix size which is substantially less than the matrix size of the initial image. A region-growing procedure is applied to the phase vector image to remove phase errors therefrom. Thereupon, the phase vector image is zoomed or expanded to a matrix of the same size as the initial image matrix. For multi-slice imaging where TI time is comparatively long, the method may employ a distributed interleave mode of data acquisition to reduce total imaging time. In such arrangement, the inversion pulse for a particular slice is placed in between the imaging pulses for two other slices. Moreover, in the method of the invention the image intensity in the phase-sensitive inversion recovery is made proportional to the physical magnetization. Accordingly, tissues with a full range of T1's, rather than just one specific T1, can be effectively suppressed by choosing an appropriate inversion time, and by applying a simple thresholding to the phase-sensitive IR images.
|
