Reduction of FSE Cusp Artifact Using Slice Tilting

Introduction With specific combinations of B0-field, B1-field, and gradient field, peripheral signals outside the prescribed field of view (FOV) can fold back onto the image, resulting in a bright spot, a series of spots, a band, or a “feather-like” artifact along the phase encoding direction. In a fast spin echo (FSE) image, this type of artifact has been termed as cusp artifact [1,2], annefact, fold-over artifact, feather artifact, and other names. It is most commonly seen on sagittal (or coronal) spine or knee images. With the present trend of short magnets in whole-body scanner designs, the problem of the FSE cusp artifact becomes increasingly important. Current approaches to attack this problem involve substantial hardware modification [3], sophisticated image reconstruction [4-5], or use of metal shields which may cause localized RF power deposition. These approaches, while effective, may not be easily implementable on all MRI scanners. We propose a technique to reduce the FSE cusp artifact by a simple pulse sequence modification.