Target volume coronary MRA revisited: usefulness of non-rigid reregistration of multi-frame 3D MRA acquisitions at 3T

Background Free-breathing whole-heart coronary MR angiography (MRA) is an established method that can visualize all coronary arteries within a single acquisition. However, a long acquisition time and suboptimal arterial signal due to thick SLAB are major limitations of 3T gradient-echo whole-heart coronary MRA without contrast. Alternatively, target-volume coronary MRA can be used to visualize coronary arteries within a predefined target volume within a shorter acquisition time. In addition, relatively small SLAB volume of this approach permits acquisitions of multi-frame 3D data without prolonging scan duration. Recently, non-rigid image registration has been emerged as a technique which can merge images and improve SNR and CNR. The purpose of this study was to develop a new technique to obtain high quality free-breathing target-volume coronary MRA with shorter acquisition time by employing multi-frame 3D acquisitions and non-rigid image registration.