Abstract: A method is provided for 3-D MR imaging of structure such as a cardiac region of a subject, which is disposed to cyclical motion. The method comprises detecting commencement of each of a succession of motion cycles, and acquiring a set of MR views of the region during each motion cycle. Each view is at a known radial distance from the center of a two-dimensional k-space, and each set includes a view of lowest spatial frequency, which is located proximate to the k-space center. The order in which the views of respective sets are acquired is selected so that the lowest frequency views of respective sets are each acquired at the same specified time, following commencement of their respectively corresponding motion cycles. The views of each set collectively define a segment in the k-space, respective segments being placed in an interleaved spiral or elliptical arrangement with respect to one another.

Abstract: An MRI system acquires NMR signals at a fixed sample rate. The acquired NMR signals are decimated to produce an output NMR signal at a prescribed sample rate. The acquired NMR signal is fast Fourier transformed to the frequency domain, and additional signal samples are produced by phase shifting in the frequency domain. The frequency domain signal samples needed to produce the prescribed sample rate are then fast Fourier transformed back to the time domain to produce the output NMR signal.

Abstract: An MRI system acquires NMR signals at a fixed sample rate. The acquired NMR signals are decimated to produce an output NMR signal at a prescribed sample rate. The acquired NMR signal is converted to a two-dimensional array and then transformed to the frequency domain by performing a DFT along one dimension of the array and a FFT along the other dimension. The resulting frequency domain data is filtered to the prescribed bandwidth and Fourier transformed back to the time domain.