Ciobanu Luisa, Solomon Eddy, Pyatigorskaya Nadya, Roussel Tangi, Le Bihan Denis, Frydman Lucio
NeuroSpin, Commissariat à l'Energie Atomique et aux Energies Alternatives, Gif-sur-Yvette, France.
Weizmann Institute of Science, Rehovot, Israel.
Neuroimage. 2015 Jun;113:37-43. doi: 10.1016/j.neuroimage.2015.03.018. Epub 2015 Mar 18.
This manuscript examines the origins and nature of the function-derived activation detected by magnetic resonance imaging at ultrahigh fields using different encoding methods. A series of preclinical high field (7 T) and ultra-high field (17.2 T) fMRI experiments were performed using gradient echo EPI, spin echo EPI and spatio-temporally encoded (SPEN) strategies. The dependencies of the fMRI signal change on the strength of the magnetic field and on different acquisition and sequence parameters were investigated. Artifact-free rat brain images with good resolution in all areas, as well as significant localized activation maps upon forepaw stimulation, were obtained in a single scan using fully refocused SPEN sequences devoid of T2* effects. Our results showed that, besides the normal T2-weighted BOLD contribution that arises in spin-echo sequences, fMRI SPEN signals contain a strong component caused by apparent T1-related effects, demonstrating the potential of such technique for exploring functional activation in rodents and on humans at ultrahigh fields.
本手稿研究了使用不同编码方法在超高场通过磁共振成像检测到的功能衍生激活的起源和性质。使用梯度回波EPI、自旋回波EPI和时空编码（SPEN）策略进行了一系列临床前高场（7T）和超高场（17.2T）功能磁共振成像实验。研究了功能磁共振成像信号变化对磁场强度以及不同采集和序列参数的依赖性。使用无T2*效应的完全重聚焦SPEN序列，在单次扫描中获得了所有区域具有良好分辨率的无伪影大鼠脑图像，以及前爪刺激后的显著局部激活图。我们的结果表明，除了自旋回波序列中出现的正常T2加权BOLD贡献外，功能磁共振成像SPEN信号还包含由明显的T1相关效应引起的强成分，证明了该技术在超高场探索啮齿动物和人类功能激活的潜力。
