- Oral presentation
- Open Access
Target volume coronary MRA revisited: usefulness of non-rigid reregistration of multi-frame 3D MRA acquisitions at 3T
© Ishida et al; licensee BioMed Central Ltd. 2015
- Published: 3 February 2015
- Target Volume
- Short Acquisition Time
- Subjective Image Quality
- Image Quality Score
- Image Registration Technique
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.
Six healthy volunteers underwent target volume coronary MRA and whole heart coronary MRA by using a TFE sequence with T2 preparation and fat saturation at 3T. For target volume coronary MRA, three successive 3D datasets were acquired separately for RCA and LCA during diastole (SNSE factor= 3; acquisition duration per cardiac cycle =30ms for RCA, 50ms for LCA; navigator gating window = 3mm; resolution =1.3x1.3x3.0 mm; slab thickness=4.5cm). Three-point planning system was used to define the imaging plane. Target volume MRA images were merged by using a non-rigid image registration technique optimized for coronary MRA. Two blinded reviewers determined SNR, CNR and a subjective quality score. Scan times for target-volume and whole-heart coronary MRA were compared for each volunteer.
SNR and CNR of coronary artery in target-volume coronary MRA.
Merged image (frame 1+2)
Merged image (frame 1+2+3)
* p<0.05, ** p<0.001
Multi-frame 3D acquisitions and non-rigid image reregistration allow for acquisition of free-breathing target volume 3T coronary MRA with the image quality that is superior to the single-frame acquisition, within a significantly shorter acquisition time compared to whole heart coronary MRA.
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