Preliminary investigation of respiratory self‐gating for free‐breathing segmented cine MRI

Abstract

Segmented cine MRI generally requires breath‐holding, which can be problematic for many patients. Navigator echo techniques, particularly successful for free‐breathing coronary MRA, are incompatible with the acquisition strategies and SSFP pulse sequences commonly used for cine MRI. The purpose of this work is to introduce a new self‐gating technique deriving respiratory gating information directly from the raw imaging data acquired for segmented cine MRI. The respiratory self‐gating technique uses interleaved radial k‐space sampling to provide low‐resolution images in real time during the free‐breathing acquisition that are compared to target expiration images. Only the raw data‐producing images with high correlation to the target images are included in the final high‐resolution reconstruction. The self‐gating technique produced cine series with no significant differences in quantitative image sharpness to series produced using comparable breath‐held techniques. Because of the difficulties associated with breath‐holding, the respiratory self‐gating technique represents an important practical advance for cardiac MRI. Magn Reson Med 53:159–168, 2005. Published 2004 Wiley‐Liss, Inc.