Levy L M, Henkin R I, Hutter A, Lin C S, Schellinger D
Department of Radiology, Georgetown University Hospital, Washington, D.C., USA.
J Comput Assist Tomogr. 1998 Jan-Feb;22(1):96-103. doi: 10.1097/00004728-199801000-00019.
Our goal was to use functional MRI (fMRI) to develop an objective, noninvasive technique by which patients with smell loss can be identified, their abnormalities quantitated, their results compared with findings in normal subjects, and visual representation of their CNS pathology obtained.
Functional MR brain scans were obtained in eight patients with hyposmia in response to three olfactory stimuli (pyridine, menthone, amyl acetate) in three coronal brain sections selected from anterior to posterior temporal brain regions using multislice FLASH MRI. Results were compared with similar studies performed in 17 normal subjects. Activation images were derived using correlation analysis, and ratios of area of brain activated to total brain area were obtained.
Brain activation to each stimulus was lower in each section in patients compared with normal subjects and reached statistical significance for mean activation for each odor and in six of the nine individual sections studied. Activation in patients was found in regions previously associated with CNS processing of olfactory stimuli in normal subjects, but activation in patients was much less, particularly in inferior frontal and cingulate gyral regions of frontal cortex and in regions of medial and posterior temporal cortex.
These results demonstrate quantitative CNS changes in smell function in response to olfactory stimuli in patients with hyposmia, demonstrate a novel, objective method by which these patients can be identified, and provide maps of the CNS changes associated with their smell loss.
我们的目标是利用功能磁共振成像（fMRI）开发一种客观、无创的技术，通过该技术可以识别嗅觉丧失患者，对其异常情况进行量化，将其结果与正常受试者的检查结果进行比较，并获得其中枢神经系统（CNS）病理学的可视化表现。
对8名嗅觉减退患者进行了功能性磁共振脑扫描，使用多层快速低角度激发（FLASH）磁共振成像技术，在从颞叶脑区前部到后部选取的三个冠状脑切片中，对三种嗅觉刺激（吡啶、薄荷酮、乙酸戊酯）做出反应。将结果与17名正常受试者进行的类似研究进行比较。使用相关性分析得出激活图像，并获得脑激活面积与全脑面积的比率。
与正常受试者相比，患者每个脑切片对每种刺激的脑激活程度均较低，并且每种气味的平均激活程度以及所研究的九个个体脑切片中的六个切片均达到统计学显著性。在患者中发现的激活区域与正常受试者中先前与嗅觉刺激的中枢神经系统处理相关的区域相同，但患者的激活程度要低得多，尤其是在额叶皮质的额下回和扣带回区域以及颞叶内侧和后部皮质区域。
这些结果证明了嗅觉减退患者对嗅觉刺激做出反应时中枢神经系统嗅觉功能的定量变化，证明了一种可以识别这些患者的新颖、客观的方法，并提供了与他们嗅觉丧失相关的中枢神经系统变化图谱。
