The objective of this grant is to further develop and test the feasibility of a class of MR angiographic pulse sequences generally referred to as 3D TRICKS (3D Time-resolved Imaging of Contrast using time interpolated and shared k-Space). These sequences are made up of combinations of the following elements: variable rate k-space sampling, a recently introduced reduced field of view method, temporally interpolated k-space views and temporal view sharing. These elements permit acquisition of a temporal sequence of 3D data sets with temporal sampling of about one image volume every two seconds. These sequences have potential in a number of angiographic applications, particularly in connection with the use of first-pass intravenous Gadolinium contrast and permit the full range of temporal processing algorithms used in DSA. The proposed technique, which may be regarded as 3D MR version of intravenous DSA, offers significant advantages relative to IV-DSA and more recently introduced IV-CTA. These advantages, only some of which are associated with either of the previous techniques, include: high SNR, temporal resolution, ability to reformat and reproject, low contrast toxicity, no ionizing radiation, and relative insensitivity to the shape and timing of the contrast pass curve. We propose here to develop, test and refine sequences tailored to the temporal characteristics and resolution requirements of several potential angiographic applications and to bring them to the point where detailed clinical evaluation, not proposed in this application, is justified.
