Optimization of blood oxygenation level-dependent sensitivity in magnetic resonance imaging using intermolecular double-quantum coherence.
Optimization of blood oxygenation level-dependent sensitivity in magnetic resonance imaging using intermolecular double-quantum coherence.
复制标题
使用分子间双量子相干性优化磁共振成像中血氧水平依赖性灵敏度。
DOI：
10.1002/jmri.10208
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
You,Zhiyang
中科院分区：
文献类型：
--
作者：
Zhong,Jianhui;Chen,Zhong;Kwok,WEdmund;Kennedy,Scott;You,Zhiyang
PurposeTo optimize timing parameters in an intermolecular double‐quantum coherence (iDQC) imaging pulse sequence for overall image signal‐to‐noise ratio (SNR) and blood oxygenation level‐dependent (BOLD) sensitivity for brain functional imaging.Material and MethodsFresh human blood was measured under different oxygenation conditions, and human brain functional magnetic resonance (fMR) images in three normal volunteers were obtained, using iDQC techniques at 1.5 T. The dependence of SNR and BOLD sensitivity was measured as a function of time delays after the iDQC evolution period.ResultsA time delay after the iDQC evolution period τ can be adjusted either to refocus the dephasing accumulated during τ, thus increasing SNR, with full rephasing occurring atdelay= ±2τ (for iDQC ordern= ±2), or to enhance BOLD effects with consequent reduced image SNR atdelay= 0.ConclusionImage SNR and BOLD sensitivity often impose different requirements for iDQC image sequence design and timing parameter selections. It is therefore important to select properly relevant parameters for different applications. J. Magn. Reson. Imaging 2002;16:733–740. © 2002 Wiley‐Liss, Inc.
