In‐plane simultaneous multisegment imaging using a 2D RF pulse. Issue 1 (4th August 2021)

• Record Type: Journal Article
• Authors: Sun, Kaibao; Zhong, Zheng; Xu, Zhongbiao; Dan, Guangyu; Karaman, M. Muge; Zhou, Xiaohong Joe
• Is Part Of: Magnetic resonance in medicine. Volume 87:Issue 1(2022)
• Page Start: 263
• Page End: 271
• Publication Date: 2021-08-04
• Subjects: 2D RF pulse -- DWI -- parallel imaging -- reduced FOV -- simultaneous multisegment imaging; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.28956
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To develop an in‐plane simultaneous multisegment (IP‐SMS) imaging technique using a 2D‐RF pulse and to demonstrate its ability to achieve high spatial resolution in EPI while reducing image distortion. Methods: The proposed IP‐SMS technique takes advantage of periodic replicates of the excitation profile of a 2D‐RF pulse to simultaneously excite multiple segments within a slice. These segments were acquired over a reduced FOV and separated using a joint GRAPPA reconstruction by leveraging virtual coils that combined the physical coil sensitivity and 2D‐RF pulse spatial response. Two excitations were used with complementary spatial response profiles to adequately cover a full FOV, producing a full‐FOV image that had the benefits of reduced FOV with high spatial resolution and reduced distortion. The IP‐SMS technique was implemented in a diffusion‐weighted single‐shot EPI sequence. Experimental demonstrations were performed on a phantom and healthy human brain. Results: In the phantom experiment, IP‐SMS enabled a four‐fold acceleration using an eight‐channel coil without causing residual aliasing artifacts. In the human brain experiment, diffusion‐weighted images with high in‐plane resolution (1 × 1 mm 2 ) and substantially reduced image distortion were obtained in all imaging planes in comparison with a commercial diffusion‐weighted EPI sequence. The capability of IP‐SMS for contiguous whole‐brain coverage was also demonstrated. Conclusion: The proposed IP‐SMS technique can realize the benefits of reduced‐FOV imaging while achieving a full‐FOV coverage with good image quality and time efficiency.