Papke K, Reimer P, Renger B, Schuierer G, Knecht S, Schulz M, Heindel W
Department of Clinical Radiology, University of Münster, Germany.
AJNR Am J Neuroradiol. 2000 Feb;21(2):395-401.
One application of functional MR imaging is to identify the primary sensorimotor cortex (M1 and S1) around the central sulcus before brain surgery. However, it has been shown that undesirable coactivation of nonprimary motor areas, such as the supplementary motor area and the premotor area, can interfere with the identification of the primary motor cortex, especially in patients with distorted anatomic landmarks. We therefore sought to design a simple functional MR imaging paradigm for selective activation of the primary sensorimotor cortex.
Different paradigms using finger tapping for motor activation were examined and compared with respect to the distribution of activated voxels in primary and nonprimary cortical areas. Studies were conducted in 14 healthy volunteers using a blood oxygen level-dependent multislice echo-planar imaging sequence.
The most selective activation of the primary sensorimotor cortex was obtained with a paradigm combining right-sided finger tapping as the activation condition with left-sided finger tapping as the control condition. Analysis of the signal time course of primary and nonprimary areas revealed that the highly selective primary motor activation was due to it being restricted to contralateral finger movements, as opposed to the nonprimary motor areas, which were activated by ipsilateral, contralateral, and bilateral finger movements alike.
When performing functional MR imaging to determine the location of the primary sensorimotor cortex, one should compare unilateral voluntary movements as the activation condition with contralateral movements as the control condition to accentuate activation of the primary motor area and to suppress undesirable coactivation of nonprimary motor areas.
功能磁共振成像的一个应用是在脑手术前识别中央沟周围的主要感觉运动皮层（M1和S1）。然而，已经表明，非主要运动区域（如辅助运动区和运动前区）的不良共激活会干扰主要运动皮层的识别，尤其是在解剖标志扭曲的患者中。因此，我们试图设计一种简单的功能磁共振成像范式，用于选择性激活主要感觉运动皮层。
研究并比较了使用手指敲击进行运动激活的不同范式，涉及主要和非主要皮质区域中激活体素的分布。对14名健康志愿者进行了研究，使用血氧水平依赖的多层回波平面成像序列。
通过将右侧手指敲击作为激活条件与左侧手指敲击作为对照条件相结合的范式，获得了主要感觉运动皮层的最具选择性的激活。对主要和非主要区域的信号时间进程分析表明，高度选择性的主要运动激活是由于其仅限于对侧手指运动，这与非主要运动区域不同，后者由同侧、对侧和双侧手指运动激活。
在进行功能磁共振成像以确定主要感觉运动皮层的位置时，应将单侧自主运动作为激活条件与对侧运动作为对照条件进行比较，以增强主要运动区域的激活并抑制非主要运动区域的不良共激活。
