Sorensen A G, Wray S H, Weisskoff R M, Boxerman J L, Davis T L, Caramia F, Kwong K K, Stern C E, Baker J R, Breiter H
Department of Radiology, Massachusetts General Hospital, Boston 02114, USA.
AJNR Am J Neuroradiol. 1995 Oct;16(9):1753-62.
(1) To determine whether functional MR can reliably map functional deficits in patients with stroke in the primary visual cortex; (2) to determine whether functional MR can reliably map perfusion deficits; and (3) to determine whether functional MR can give any additional diagnostic information beyond conventional MR.
Seven patients who had had a stroke in their primary visual system were examined using two functional MR techniques: (1) dynamic susceptibility contrast imaging, and (2) cortical activation mapping during full-field visual stimulation. Maps of relative cerebral blood volume and activation were created and compared with visual field examinations and conventional T2-weighted images on a quadrant-by-quadrant basis in five of these patients.
Visual field mapping matched with both T2-weighted conventional images and activation mapping of 16 of 18 quadrants. In two quadrants, the activation maps detected abnormalities that were present on the visual field examination but not present on the T2-weighted images nor on the relative cerebral blood volume maps, which may indicate abnormal function without frank infarction. In addition, the activation maps demonstrated decreased activation in extrastriate cortex and had normal T2 signal and relative cerebral blood volume but was adjacent to infarcted primary cortex, mapping in vivo how stroke in one location can affect the function of distant tissue.
Functional MR techniques can accurately map functional and perfusion deficits and thereby provide additional clinically useful information. Additional studies will be needed to determine the prognostic utility of functional MR in stroke patients.
（1）确定功能磁共振成像（fMRI）能否可靠地描绘原发性视觉皮层中风患者的功能缺陷；（2）确定fMRI能否可靠地描绘灌注缺陷；（3）确定fMRI能否提供超越传统磁共振成像（MR）的任何额外诊断信息。
使用两种fMRI技术对7例原发性视觉系统中风患者进行检查：（1）动态磁敏感对比成像，（2）全视野视觉刺激期间的皮层激活图谱绘制。在其中5例患者中，逐象限创建相对脑血容量和激活图谱，并与视野检查及传统T2加权图像进行比较。
视野图谱与18个象限中的16个象限的T2加权传统图像及激活图谱相匹配。在两个象限中，激活图谱检测到视野检查中存在但T2加权图像和相对脑血容量图谱中未出现的异常，这可能表明存在无明显梗死的功能异常。此外，激活图谱显示纹外皮层激活降低，T2信号和相对脑血容量正常，但与梗死的初级皮层相邻，描绘了体内一个部位的中风如何影响远处组织的功能。
fMRI技术能够准确描绘功能和灌注缺陷，从而提供额外的临床有用信息。需要进一步研究以确定fMRI在中风患者中的预后效用。
