k-space weighted image contrast (KWIC) for contrast manipulation in projection reconstruction MRI

A novel technique for manipulating contrast in projection reconstruction MR I is described. The method takes advantage of the fact that the central reg ion of k-space is oversampled, allowing one to choose different filters to enhance or reduce the amount that each view contributes to the central regi on, which dominates image contrast. The technique is implemented into a fas t spin-echo (FSE) sequence, and it is shown that multiple T-2-weighted imag es can be reconstructed from a single image data set. These images are show n to be nearly identical to those acquired with the Cartesian-sampled FSE s equence at different effective echo times. Further, it is demonstrated that T-2 maps can be generated from a single image data set. This technique als o has the potential to be useful in dynamic contrast enhancement studies, c apable of yielding a series of images at a significantly higher effective t emporal resolution than what is currently possible with other methods, with out sacrificing spatial resolution. (C) 2000 Wiley-Liss, Inc.