Sampling Strategies for MRI with Simultaneous Excitation and Acquisition

Introduction Imaging of samples with very short T2 requires data acquisition to start immediately after excitation. In the SWIFT technique [1] this is accomplished by playing out a gapped frequency-swept pulse while concurrently acquiring data during the gaps. At the same time gradients are applied permanently and stepped in a 3D radial mode. Thus SWIFT combines the short-T2 capability of the silent radial FID method [2] with the ability of swept RF pulses to cover large bandwidths under B1 restrictions [3, 4]. Within the general concept of simultaneous excitation and acquisition (SEA) introduced with the SWIFT technique, we suggest a number of improved sampling strategies, addressing reconstruction stability, SNR, and artefacts related to pulse errors [3, 5].