Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK.
Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK.
Sci Rep. 2024 Sep 4;14(1):20591. doi: 10.1038/s41598-024-70892-8.
As hyperpolarized (HP) carbon-13 (C) metabolic imaging is clinically translated, there is a need for easy-to-implement, fast, and robust imaging techniques. However, achieving high temporal resolution without decreasing spatial and/or spectral resolution, whilst maintaining the usability of the imaging sequence is challenging. Therefore, this study looked to accelerate HP C MRI by combining a well-established and robust sequence called two-dimensional Chemical Shift Imaging (2D CSI) with prospective under sampling and SENSitivity Encoding (SENSE) reconstruction. Due to the low natural abundance of C, the sensitivity maps cannot be pre-acquired for the reconstruction. As such, the implementation of sodium (Na) sensitivity maps for SENSE reconstructed C CSI was demonstrated in a phantom and in vivo in the pig kidney. Results showed that SENSE reconstruction using Na sensitivity maps corrected aliased images with a four-fold acceleration. With high temporal resolution, the kidney spectra produced a detailed metabolic arrival and decay curve, useful for further metabolite kinetic modelling or denoising. Metabolic ratio maps were produced in three pigs demonstrating the technique's ability for repeat metabolic measurements. In cases with unknown metabolite spectra or limited HP MRI specialist knowledge, this robust acceleration method ensures comprehensive capture of metabolic signals, mitigating the risk of missing spectral data.
随着超极化（HP）碳-13（C）代谢成像是临床转化的需要，需要易于实施、快速和稳健的成像技术。然而，在不降低空间和/或光谱分辨率的情况下实现高时间分辨率，同时保持成像序列的可用性是具有挑战性的。因此，本研究旨在通过结合一种成熟且稳健的序列，即二维化学位移成像（2D CSI），与前瞻性欠采样和灵敏度编码（SENSE）重建相结合，来加速 HP C MRI。由于 C 的天然丰度低，无法预先获取用于重建的灵敏度图。因此，在体模和猪肾中证明了 SENSE 重建中使用 Na 灵敏度图对 C CSI 进行校正的方法。结果表明，使用 Na 灵敏度图进行 SENSE 重建可以校正四倍加速的混叠图像。具有高时间分辨率，肾脏光谱产生了详细的代谢到达和衰减曲线，可用于进一步的代谢物动力学建模或去噪。在三只猪中生成了代谢比图，证明了该技术进行重复代谢测量的能力。在未知代谢物光谱或有限的 HP MRI 专业知识的情况下，这种稳健的加速方法确保了代谢信号的全面捕获，降低了错过光谱数据的风险。
