Highly efficient whole-heart imaging using radial phase encoding-phase ordering with automatic window selection.

Three dimensional (3D) whole-heart magnetic resonance imaging (MRI) has become an important imaging modality to assess cardiovascular diseases. The main challenges for 3D whole-heart MRI are long acquisition times, required to achieve high spatial resolution, and image artefacts due to physiological motion. Here we propose to overcome these problems by the combination of an interleaved Radial Phase Encoding trajectory and the Phase Ordering with Automatic Window Selection method. This Radial Phase Encoding-Phase Ordering with Automatic Window Selection approach yields fast 3D whole-heart imaging with a high isotropic resolution and high navigator efficiency even for extremely irregular breathing. Numerical simulations were performed and Radial Phase Encoding-Phase Ordering with Automatic Window Selection was implemented on a clinical scanner. A comparison between the proposed method and a respiratory gated 3D Cartesian approach was carried out. Radial Phase Encoding-Phase Ordering with Automatic Window Selection leads to a better depiction of coronary arteries and an increase in navigator efficiency. In addition to a high resolution image, this method also provides dynamic respiratory information without an increase in scan time.