Spectroscopic imaging with improved gradient modulated constant adiabaticity pulses on high-field clinical scanners
Spectroscopic imaging with improved gradient modulated constant adiabaticity pulses on high-field clinical scanners
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DOI：
10.1016/j.jmr.2010.01.010
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发表时间：
2010-04-01
影响因子：
2.2
通讯作者：
Sorensen, A. Gregory
中科院分区：
文献类型：
--
作者：
Andronesi, Ovidiu C.;Ramadan, Saadallah;Sorensen, A. Gregory
这项工作的目的是设计和实现恒定绝热梯度调制脉冲，该脉冲在配备标准硬件的3T临床扫描仪上改善了切片轮廓并减少了频谱成像伪影。新提出的脉冲是使用梯度偏移独立绝热性(GOIA)设计的。Tannus和Garwood[13])使用Wurst调制处理RF和梯度波形的方法。将GOIA-Wurst脉冲与相同带宽和持续时间的GOIA-HSN(基于n阶双曲正割的GOIA)和FOCI(频偏校正反转)脉冲进行了比较。给出了体模和健康志愿者的数值模拟和实验测量结果。GoIA-Wurst脉冲提供了改进的切片轮廓，与GoIA-HSN脉冲相比，对于非共振频率具有更少的切片涂抹。GOIA-Wurst的射频波幅峰值远低于FOCI(低40%)，但略高于GOIA-HSN(高14.9%)。通过对线形、涡流伪影、皮下脂肪污染和信噪比的分析表明，Goia-Wurst的频谱质量得到了改善。在这项工作中测试的Goia-Wurst脉冲表明，在常规的临床设置中可以获得可靠的光谱成像，并可能促进临床光谱的使用。(C)2010 Elsevier Inc.保留所有权利。
The purpose of this work was to design and implement constant adiabaticity gradient modulated pulses that have improved slice profiles and reduced artifacts for spectroscopic imaging on 3 T clinical scanners equipped with standard hardware. The newly proposed pulses were designed using the gradient offset independent adiabaticity (GOIA. Tannus and Garwood [13]) method using WURST modulation for RF and gradient waveforms. The GOIA-WURST pulses were compared with GOIA-HSn (GOIA based on nth-order hyperbolic secant) and FOCI (frequency offset corrected inversion) pulses of the same bandwidth and duration. Numerical simulations and experimental measurements in phantoms and healthy volunteers are presented. GOIA-WURST pulses provide improved slice profile that have less slice smearing for off-resonance frequencies compared to GOIA-HSn pulses. The peak RF amplitude of GOIA-WURST is much lower (40% less) than FOCI but slightly higher (14.9% more) to GOIA-HSn. The quality of spectra as shown by the analysis of lineshapes, eddy currents artifacts, subcutaneous lipid contamination and SNR is improved for GOIA-WURST. GOIA-WURST pulse tested in this work shows that reliable spectroscopic imaging could be obtained in routine clinical setup and might facilitate the use of clinical spectroscopy. (C) 2010 Elsevier Inc. All rights reserved.