ECLIPSE utilizing gradient-modulated offset-independent adiabaticity (GOIA) pulses for highly selective human brain proton MRSI.
ECLIPSE utilizing gradient-modulated offset-independent adiabaticity (GOIA) pulses for highly selective human brain proton MRSI.
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DOI：
10.1002/nbm.4415
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发表时间：
2021-01
影响因子：
2.9
通讯作者：
de Graaf, Robin A.
中科院分区：
文献类型：
--
作者：
Kumaragamage, Chathura;De Feyter, Henk M.;Brown, Peter;McIntyre, Scott;Nixon, Terence W.;de Graaf, Robin A.
对于质子磁共振成像采集，存在多种颅外脂肪抑制方法。流行的和新兴的脂类抑制方法都有其固有的一组优缺点，涉及可实现的脂类抑制水平、射频功率沉积、对B1+场和脂类T1异质性的不敏感性、脑覆盖、空间选择性、化学位移(CSD)误差以及跨越0.9-4.7ppm波段的光谱数据的可靠性。脉冲二阶场椭圆定位(ECLIPSE)的实用性先前已经被证明在颅外脂肪抑制和使用3 kHz带宽AFP脉冲的低功率需求方面是>；100倍。像所有基于梯度的定位方法一样，ECLIPSE对CSD误差很敏感，导致ROI边缘体素的新陈代谢曲线被修改。本文基于梯度偏置无关绝热(GOIA)算法，对ECLIPSE进行了扩展，引入了带宽为15 kHz的二阶梯度调制射频脉冲，大大降低了CSD，改善了空间选择性。实现了绝热双自旋回波食内体积选择方法(TE=45ms)和食外体积抑制(TE=3.2ms)FID-MRSI方法。两个Goia-eclipse MRSI序列都提供了体内无伪影的代谢物光谱，在脂质抑制方面达到了100倍，平面内CSD为2.6 mm，ROI边缘体素的过渡宽度为3.3 mm，与母公司的非梯度调制方法相比，提高了~5倍。尽管带宽增加了五倍，Goia-eclipse只需要增加1.9倍的射频功率。高度稳健的脂肪抑制与低CSD和尖锐的ROI边缘转变相结合，使Goia-eclipse成为通常使用的脂肪抑制方法的有吸引力的替代方案。此外，低射频功率沉积表明GOIA-ECLIPSE非常适合高场(≥3T)磁共振成像应用。
A multitude of extracranial lipid suppression methods exist for proton MRSI acquisitions. Popular and emerging lipid suppression methods each have their inherent set of advantages and disadvantages related to the achievable level of lipid suppression, RF power deposition, insensitivity to B1+ field and lipid T1 heterogeneity, brain coverage, spatial selectivity, chemical shift displacement (CSD) errors, and reliability of spectroscopic data spanning the observed 0.9 – 4.7 ppm band. The utility of elliptical localization with pulsed second order fields (ECLIPSE) was previously demonstrated with > 100-fold in extracranial lipid suppression and low power requirements utilizing 3 kHz bandwidth AFP pulses. Like all gradient-based localization methods, ECLIPSE is sensitive to CSD errors, resulting in a modified metabolic profile in edge-of-ROI voxels. In this work, ECLIPSE is extended with 15 kHz bandwidth second-order-gradient-modulated RF pulses based on the gradient offset-independent adiabaticity (GOIA) algorithm to greatly reduce CSD, and improve spatial selectively. An adiabatic double spin-echo ECLIPSE inner volume selection (TE = 45 ms) MRSI method, and an ECLIPSE outer volume suppression (TE = 3.2 ms) FID-MRSI method were implemented. Both GOIA-ECLIPSE MRSI sequences provided artifact free metabolite spectra in vivo, with > 100-fold in lipid suppression and < 2.6 mm in-plane CSD and < 3.3 mm transition width for edge-of-ROI voxels, representing a ~ 5-fold improvement compared to the parent, non-gradient-modulated method. Despite the five-fold larger bandwidth, GOIA-ECLIPSE only required a 1.9-fold increase in RF power. The highly robust lipid suppression combined with low CSD and sharp ROI edge transitions make GOIA-ECLIPSE an attractive alternative to commonly employed lipid suppression methods. Furthermore, the low RF power deposition demonstrates that GOIA-ECLIPSE is very well suited for high-field (≥ 3 T) MRSI applications.
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影响因子：
2.9
作者：
de Graaf RA;Brown PB;De Feyter HM;McIntyre S;Nixon TW
通讯作者：
Nixon TW
影响因子：
3.3
作者：
Avdievich, Nikolai I.;Giapitzakis, Ioannis-Angelos;Henning, Anke
通讯作者：
Henning, Anke
影响因子：
3.3
作者：
Boer, Vincent O.;van de Lindt, Tessa;Klomp, Dennis W. J.
通讯作者：
Klomp, Dennis W. J.
影响因子：
3.3
作者：
Howe, FA;Barton, SJ;Griffiths, JR
通讯作者：
Griffiths, JR
影响因子：
8.3
作者：
Graham, GD;Hwang, JH;Prichard, JW
通讯作者：
Prichard, JW