Improvement of the SNR-resolution compromise in MRA using spatial segmented k-space acquisitions
A method is proposed to reconstruct Magnetic Resonance Angiography (MRA) volumes from successive acquisitions. A specific set up of the MR system is used to acquire highly anisotropic MRA volumes with reduced k-space coverage. These partial k-spaces are then combined to obtain a 3D k-space fitted to the frequency support of the angiographic image. This allows us to improve the SNR-resolution compromise of MRA by focusing the acquisition on the meaningful k-space regions. The reconstruction is performed in the image domain by minimizing a convex energy function using a gradient like method. Introduction of priors still further improves this compromise. The method is illustrated on a lucite stenosis phantom and a carotid MRA examination.