Geißler A, Matt E, Fischmeister F, Wurnig M, Dymerska B, Knosp E, Feucht M, Trattnig S, Auff E, Fitch W T, Robinson S, Beisteiner R
Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Austria; High Field MR Center, Medical University of Vienna, Austria; Department of Neurology, Medical University of Vienna, Austria.
High Field MR Center, Medical University of Vienna, Austria; Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.
Neuroimage. 2014 Dec;103:163-170. doi: 10.1016/j.neuroimage.2014.09.036. Epub 2014 Sep 22.
Several investigations have shown limitations of fMRI reliability with the current standard field strengths. Improvement is expected from ultra highfield systems but studies on possible benefits for cognitive networks are lacking. Here we provide an initial investigation on a prominent and clinically highly-relevant cognitive function: language processing in individual brains. 26 patients evaluated for presurgical language localization were investigated with a standardized overt language fMRI paradigm on both 3T and 7T MR scanners. During data acquisition and analysis we made particular efforts to minimize effects not related to static magnetic field strength differences. Six measures relevant for functional activation showed a large dissociation between essential language network nodes: although in Wernicke's area 5/6 measures indicated a benefit of ultra highfield, in Broca's area no comparison was significant. The most important reason for this discrepancy was identified as being an increase in susceptibility-related artifacts in inferior frontal brain areas at ultra high field. We conclude that functional UHF benefits are evident, however these depend crucially on the brain region investigated and the ability to control local artifacts.
多项研究表明，当前标准场强下功能磁共振成像（fMRI）的可靠性存在局限性。超高场系统有望带来改进，但缺乏关于认知网络可能受益的研究。在此，我们对一种突出且临床高度相关的认知功能进行了初步研究：个体大脑中的语言处理。对26名接受术前语言定位评估的患者，使用标准化的公开语言fMRI范式在3T和7T磁共振成像（MR）扫描仪上进行了研究。在数据采集和分析过程中，我们特别努力将与静磁场强度差异无关的影响降至最低。与功能激活相关的六项指标显示，基本语言网络节点之间存在很大差异：尽管在韦尼克区，5/6项指标表明超高场有优势，但在布洛卡区，比较结果无显著差异。这种差异的最重要原因被确定为超高场下额叶下部脑区与敏感性相关伪影的增加。我们得出结论，超高频功能的益处是明显的，然而这些益处关键取决于所研究的脑区以及控制局部伪影的能力。
