Ultra-High-Field MR Neuroimaging.
Ultra-High-Field MR Neuroimaging.
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DOI：
10.3174/ajnr.a4180
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发表时间：
2015-07
期刊：
影响因子：
--
通讯作者：
Naidich TP
中科院分区：
文献类型：
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作者：
Balchandani P;Naidich TP
在超高磁场下，如7T，MR成像可以通过增强的对比机制以前所未有的细节非侵入性地可视化大脑。在7T条件下，SNR增加和对比度增强可实现更高分辨率的解剖和血管成像。更大的光谱分离改善了光谱成像中代谢物的检测和表征。增强的血氧水平依赖性对比度提供更高分辨率的功能性MR成像。超高场磁共振成像也有利于非质子核，如钠和磷的成像。这些改进的成像方法可应用于检测与广泛的神经系统疾病相关的细微解剖、功能和代谢异常，包括癫痫、脑肿瘤、多发性硬化、阿尔茨海默病和精神疾病。然而，在7T下，物理和硬件限制导致传统MR成像脉冲序列产生伪影，需要专门的脉冲序列和新的硬件解决方案来最大化信号和对比度的高场增益。超高场MR成像的实际考虑因素包括成本、选址和患者体验。
At ultra-high magnetic fields, such as 7T, MR imaging can noninvasively visualize the brain in unprecedented detail and through enhanced contrast mechanisms. The increased SNR and enhanced contrast available at 7T enable higher resolution anatomic and vascular imaging. Greater spectral separation improves detection and characterization of metabolites in spectroscopic imaging. Enhanced blood oxygen level–dependent contrast affords higher resolution functional MR imaging. Ultra-high-field MR imaging also facilitates imaging of nonproton nuclei such as sodium and phosphorus. These improved imaging methods may be applied to detect subtle anatomic, functional, and metabolic abnormalities associated with a wide range of neurologic disorders, including epilepsy, brain tumors, multiple sclerosis, Alzheimer disease, and psychiatric conditions. At 7T, however, physical and hardware limitations cause conventional MR imaging pulse sequences to generate artifacts, requiring specialized pulse sequences and new hardware solutions to maximize the high-field gain in signal and contrast. Practical considerations for ultra-high-field MR imaging include cost, siting, and patient experience.