Abstract
Purpose: To enable fast reconstruction of undersampled motion-compensated whole-heart 3D coronary magnetic resonance angiography (CMRA) by learning a multi-scale variational neural network (MS-VNN) which allows the acquisition of high-quality 1.2 × 1.2 × 1.2 mm isotropic volumes in a short and predictable scan time. Methods: Eighteen healthy subjects and one patient underwent free-breathing 3D CMRA acquisition with variable density spiral-like Cartesian sampling, combined with 2D image navigators for translational motion estimation/compensation. The proposed MS-VNN learns two sets of kernels and activation functions for the magnitude and phase images of the complex-valued data. For the magnitude, a multi-scale approach is applied to better capture the small calibre of the coronaries. Ten subjects were considered for training and validation. Prospectively undersampled motion-compensated data with 5-fold and 9-fold accelerations, from the remaining 9 subjects, were used to evaluate the framework. The proposed approach was compared to Wavelet-based compressed-sensing (CS), conventional VNN, and to an additional fully-sampled (FS) scan. Results: The average acquisition time (m:s) was 4:11 for 5-fold, 2:34 for 9-fold acceleration and 18:55 for fully-sampled. Reconstruction time with the proposed MS-VNN was ~14 s. The proposed MS-VNN achieves higher image quality than CS and VNN reconstructions, with quantitative right coronary artery sharpness (CS:43.0%, VNN:43.9%, MS-VNN:47.0%, FS:50.67%) and vessel length (CS:7.4 cm, VNN:7.7 cm, MS-VNN:8.8 cm, FS:9.1 cm) comparable to the FS scan. Conclusion: The proposed MS-VNN enables 5-fold and 9-fold undersampled CMRA acquisitions with comparable image quality that the corresponding fully-sampled scan. The proposed framework achieves extremely fast reconstruction time and does not require tuning of regularization parameters, offering easy integration into clinical workflow.
Original language | English |
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Pages (from-to) | 155-167 |
Number of pages | 13 |
Journal | Magnetic Resonance Imaging |
Volume | 70 |
DOIs | |
Publication status | Published - Jul 2020 |
Bibliographical note
Publisher Copyright:© 2020
Funding
The authors acknowledge financial support from: (1) Engineering and Physical Sciences Research Council (EPSRC), UK: EP/P001009/1, EP/P032311/1, EPSRC EP/P007619, (2) Wellcome EPSRC Centre for Medical Engineering , UK: NS/A000049/1 , and (3) the Department of Health via the National Institute for Health Research (NIHR), UK: comprehensive Biomedical Research Centre award to Guy's & St Thomas' NHS Foundation Trust in partnership with King's College London and King's College Hospital NHS Foundation Trust. We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan V GPU used for this research. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. The authors acknowledge financial support from: (1) Engineering and Physical Sciences Research Council (EPSRC), UK: EP/P001009/1, EP/P032311/1, EPSRC EP/P007619, (2) Wellcome EPSRC Centre for Medical Engineering, UK:NS/A000049/1, and (3) the Department of Health via the National Institute for Health Research (NIHR), UK: comprehensive Biomedical Research Centre award to Guy's & St Thomas' NHS Foundation Trust in partnership with King's College London and King's College Hospital NHS Foundation Trust. We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan V GPU used for this research. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.
Funders | Funder number |
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Wellcome EPSRC | NS/A000049/1 |
NVIDIA | |
King's College Hospital NHS Foundation Trust | |
NIHR Biomedical Research Centre, Royal Marsden NHS Foundation Trust/Institute of Cancer Research | |
Engineering and Physical Sciences Research Council | EP/P032311/1, EP/P001009/1, EP/P007619 |
National Institute for Health Research | |
Department of Health and Social Care | |
King's College London | |
Department of Health, Australian Government |
Keywords
- Cardiac MRI
- Coronary imaging
- Fast imaging
- Undersampling
- Variational neural network