Cardiorenal 23Na MRI at 7.0 Tesla using a 4/4 channel 1H/23Na RF antenna array
Cardiorenal 23Na MRI at 7.0 Tesla using a 4/4 channel 1H/23Na RF antenna array
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DOI：
10.1002/mrm.27880
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发表时间：
2019-06-30
影响因子：
3.3
通讯作者：
Niendorf, Thoralf
中科院分区：
文献类型：
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作者：
Boehmert, Laura;Kuehne, Andre;Niendorf, Thoralf
目的肾综合征是一种心肾功能紊乱的疾病，其中一个器官的功能障碍引起另一个器官的功能障碍。这项工作描述了一个4/4通道氢-1/钠（H-1/Na-23）RF阵列的设计、评估和应用，该阵列专为7.0特斯拉（T）的心肾MRI定制，以更好地了解心肾综合征的生理代谢。方法双频射频阵列由平面后段和适度弯曲前段组成，每段由2个Na-23 MR专用环形单元和2个H-1 MR专用环形单元组成，并进行了电磁场和比吸收率的数值模拟。传输场（B1+）的均匀性进行了优化，并对电磁场模拟基准。进行了体内可行性研究。结果该阵列具有足够的射频特性、B1+均匀性和穿透深度，可以在7.0 T下进行心脏和肾脏的Na-23 MRI。心脏中钠的平均B1+场为7.7 +/- 0.8 mu T/根kW，肾脏中为6.9 +/- 2.3 mu T/根kW。在健康受试者中证明了RF阵列对Na-23 MRI的适用性（Na-23 MRI的采集时间：18 min;标称各向同性空间分辨率：5 mm [肾脏]和6 mm [心脏]）。结论本工作为进一步探索适用于心脏和肾脏Na-23 MRI的密集封装多通道收发器阵列提供了鼓励。有了这项技术，使用Na-23 MRI探测体内心脏和肾脏中钠浓度的能力将为破译这两个器官之间复杂的相互作用做出关键贡献。
Purpose Cardiorenal syndrome describes disorders of the heart and the kidneys in which a dysfunction of 1 organ induces a dysfunction in the other. This work describes the design, evaluation, and application of a 4/4-channel hydrogen-1/sodium (H-1/Na-23) RF array tailored for cardiorenal MRI at 7.0 Tesla (T) for a better physiometabolic understanding of cardiorenal syndrome. Methods The dual-frequency RF array is composed of a planar posterior section and a modestly curved anterior section, each section consisting of 2 loop elements tailored for Na-23 MR and 2 loopole-type elements customized for H-1 MR. Numerical electromagnetic field and specific absorption rate simulations were carried out. Transmission field (B1+) uniformity was optimized and benchmarked against electromagnetic field simulations. An in vivo feasibility study was performed. Results The proposed array exhibits sufficient RF characteristics, B1+ homogeneity, and penetration depth to perform Na-23 MRI of the heart and kidney at 7.0 T. The mean B1+ field for sodium in the heart is 7.7 +/- 0.8 mu T/root kW and in the kidney is 6.9 +/- 2.3 mu T/root kW. The suitability of the RF array for Na-23 MRI was demonstrated in healthy subjects (acquisition time for Na-23 MRI: 18 min; nominal isotropic spatial resolution: 5 mm [kidney] and 6 mm [heart]). Conclusion This work provides encouragement for further explorations into densely packed multichannel transceiver arrays tailored for Na-23 MRI of the heart and kidney. Equipped with this technology, the ability to probe sodium concentration in the heart and kidney in vivo using Na-23 MRI stands to make a critical contribution to deciphering the complex interactions between both organs.