Zhang Wei-Ting, Mainero Caterina, Kumar Ashok, Wiggins Christopher J, Benner Thomas, Purdon Patrick L, Bolar Divya S, Kwong Kenneth K, Sorensen A Gregory
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, and Harvard Medical School, Bldg 149 (2301), 13th Street, Charlestown, MA 02129, USA.
Neuroimage. 2006 Jul 15;31(4):1506-12. doi: 10.1016/j.neuroimage.2006.02.033. Epub 2006 Apr 19.
Functional magnetic resonance imaging (fMRI) has become a powerful tool for studying the normal and diseased human brain. The application of fMRI in detecting neuronal signals in the trigeminal system, however, has been hindered by low detection sensitivity due to activation artifacts caused by cardiac pulse-induced brain and brainstem movement. A variety of cardiac gating techniques have been proposed to overcome this issue, typically by phase locking the sampling to a particular time point during each cardiac cycle. We sought to compare different cardiac gating strategies for trigeminal system fMRI. In the present study, we used tactile stimuli to elicit brainstem and thalamus activation and compared the fMRI results obtained without cardiac gating and with three different cardiac gating strategies: single-echo with TR of 3 or 9 heartbeats (HBs) and dual-echo T2*-mapping EPI (TR = 2 HBs, TE = 21/55 ms). The dual-echo T2* mapping and the single-echo with TR of 2 and 3 HBs cardiac-gated fMRI techniques both increased detection rate of fMRI activation in brainstem. Activation in the brainstem and the thalamus was best detected by cardiac-gated dual-echo EPI.
功能磁共振成像（fMRI）已成为研究正常和患病人类大脑的强大工具。然而，由于心脏搏动引起的大脑和脑干运动导致的激活伪影，fMRI在检测三叉神经系统神经元信号方面的应用受到了低检测灵敏度的阻碍。已经提出了多种心脏门控技术来克服这个问题，通常是通过将采样与每个心动周期中的特定时间点进行相位锁定。我们试图比较三叉神经系统fMRI的不同心脏门控策略。在本研究中，我们使用触觉刺激来引发脑干和丘脑激活，并比较了在没有心脏门控以及采用三种不同心脏门控策略的情况下获得的fMRI结果：TR为3或9个心跳（HBs）的单回波以及双回波T2映射EPI（TR = 2 HBs，TE = 21/55 ms）。双回波T2映射以及TR为2和3 HBs的单回波心脏门控fMRI技术均提高了脑干中fMRI激活的检测率。心脏门控双回波EPI对脑干和丘脑中的激活检测效果最佳。
