Flow‐suppressed hyperpolarized 13C chemical shift imaging using velocity‐optimized bipolar gradient in mouse liver tumors at 9.4 T. Issue 5 (26th December 2016)

• Record Type: Journal Article
• Authors: Lee, Hansol; Lee, Joonsung; Joe, Eunhae; Yang, Seungwook; Song, Jae Eun; Choi, Young‐Suk; Wang, Eunkyung; Joo, Chan Gyu; Song, Ho‐Taek; Kim, Dong‐Hyun
• Is Part Of: Magnetic resonance in medicine. Volume 78:Issue 5(2017)
• Page Start: 1674
• Page End: 1682
• Publication Date: 2016-12-26
• Subjects: hyperpolarized 13C -- pyruvate -- flow suppression -- bipolar gradient -- liver tumor -- slow venous flow; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.26578
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To optimize and investigate the influence of bipolar gradients for flow suppression in metabolic quantification of hyperpolarized 13 C chemical shift imaging (CSI) of mouse liver at 9.4 T. Methods: The trade‐off between the amount of flow suppression using bipolar gradients and T 2 * effect from static spins was simulated. A free induction decay CSI sequence with alternations between the flow‐suppressed and non–flow‐suppressed acquisitions for each repetition time was developed and was applied to liver tumor–bearing mice via injection of hyperpolarized [1‐ 13 C] pyruvate. Results: The in vivo results from flow suppression using the velocity‐optimized bipolar gradient were comparable with the simulation results. The vascular signal was adequately suppressed and signal loss in stationary tissue was minimized. Application of the velocity‐optimized bipolar gradient to tumor‐bearing mice showed reduction in the vessel‐derived pyruvate signal contamination, and the average lactate/pyruvate ratio increased by 0.095 ( P < 0.05) in the tumor region after flow suppression. Conclusion: Optimization of the bipolar gradient is essential because of the short 13 C T 2 * and high signal in venous flow in the mouse liver. The proposed velocity‐optimized bipolar gradient can suppress the vascular signal, minimizing T 2 * ‐related signal loss in stationary tissues at 9.4 T. Magn Reson Med 78:1674–1682, 2017. © 2016 International Society for Magnetic Resonance in Medicine.