Rapid online deep artifact suppression for real-time spiral bSSFP CMR with blipped-CAIPI simultaneous multi-slice imaging at 1.5 T.
Authors
Affiliations (5)
Affiliations (5)
- Centre for Translational Cardiovascular Imaging, Institute of Cardiovascular Science, University College London, London, United Kingdom; Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden; Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
- Research & Collaborations GBI, Siemens Healthcare Ltd, Camberley, United Kingdom.
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden; Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
- Centre for Translational Cardiovascular Imaging, Institute of Cardiovascular Science, University College London, London, United Kingdom.
- Centre for Translational Cardiovascular Imaging, Institute of Cardiovascular Science, University College London, London, United Kingdom. Electronic address: [email protected].
Abstract
Real-time (RT) bSSFP MRI enables fast free-breathing cardiovascular imaging but requires 10-16 slices for functional assessment, resulting in prolonged scan times. Simultaneous multi-slice (SMS) imaging can reduce acquisition time but when combined with non-Cartesian trajectories, it relies on iterative reconstructions that often preclude online use. This study investigates deep artifact suppression to facilitate rapid, online reconstruction of RT-SMS. A spiral bSSFP RT sequence with SMS-2 was implemented at 1.5 T. Reconstruction used slice separation in k-space, followed by deep artifact suppression in image space using a 3D U-Net. Ten healthy volunteers were prospectively imaged. RT-SMS image quality and reconstruction time were compared between deep artifact suppression and compressed sensing (CS) reconstructions. Left (LV) and right (RV) ventricular volumes at end-diastole (EDV) and end-systole (ESV) and LV mass (LVM) were compared between RT-SMS with deep artifact suppression and reference-standard breath-hold (BH) imaging. The RT-SMS technique acquired each SMS slice-pair within a single cardiac cycle, reducing the total acquisition by ~13× compared with BH imaging (15 s vs 3 min 15 s). Total reconstruction for RT-SMS using deep artifact suppression took ~30 s, compared with 24 min 55 s for compressed sensing. Deep artifact suppression consistently outperformed CS in quantitative and qualitative image quality (p < 0.001). Functional agreement between BH and RT-SMS with deep artifact suppression was good (LVEDV: -7.5 ± 6.8 ml, LVESV: -0.9 ± 4.2 ml, RVEDV: -6.4 ± 8.4 ml, RVESV: 0.2 ± 10.7 ml, LVM: -10.3 ± 11.0 g). Online deep artifact suppression reconstruction for RT-SMS bSSFP CMR enables free-breathing short-axis coverage with a substantial reduction in acquisition and reconstruction time while maintaining diagnostic image quality.