Automated rectilinear self-gated cardiac cine imaging.

Abstract

ECG-based gating in cardiac MR imaging requires additional patient preparation time, is susceptible to RF and magnetic interference, and is ineffective in a significant percentage of patients. "Wireless" or "self-gating" techniques have been described using either interleaved central k-space lines or projection reconstruction to obtain MR signals synchronous with the cardiac cycle. However, the interleaved, central line method results in a doubling of the acquisition time, while radial streak artifacts are encountered with the projection reconstruction method. In this work, a new self-gating technique is presented to overcome these limitations. A retrospectively gated TrueFISP cine sequence was modified to acquire a short second echo after the readout and phase gradients are rewound. The information obtained from this second echo was used to derive a gating signal. This technique was compared to ECG-based gating in 10 healthy volunteers and shown to have no significant difference in image quality. The results indicate that this method could serve as an alternative gating strategy without the need for external physiological signal detection.