Yousem D M, Maldjian J A, Hummel T, Alsop D C, Geckle R J, Kraut M A, Doty R L
Department of Radiology, and Smell and Taste Center, University of Pennsylvania Medical Center, Philadelphia, USA.
AJNR Am J Neuroradiol. 1999 Apr;20(4):600-8.
The effects of age, sex, and handedness on olfaction have not been adequately addressed with odor-stimulated functional MR imaging studies. We sought to determine the effect of age on functional MR imaging experiments performed with odor stimulation.
Five right-handed subjects with a mean age of 73 years and five right-handed subjects with a mean age of 24 years underwent gradient-echo echo-planar functional MR imaging using binasal olfactory stimulation. Imaging parameters included 3000/30 (TR/TE) and a 5-mm section thickness in a 6-minute sequence with 30 seconds of pulsed odorants alternating with 30 seconds of room air. The data were normalized to a standard atlas, and individual and group statistical parametric maps (SPMs) were generated for each task. The SPMs were thresholded for a P < .01, and the volumes of activation and distribution of cluster maxima were compared for the two groups.
Analysis of the group SPMs revealed activated voxels in the frontal lobes, perisylvian regions, and cingulate gyri, with greater volume in the younger group than in the older group. The right inferior frontal, right perisylvian, and right and left cingulum had the largest number of voxels activated. The most common sites of activation on individual maps in both groups were the right inferior frontal regions and the right and left superior frontal and perisylvian zones.
Given similar olfactory task paradigms, younger subjects showed a greater number of activated voxels than did older subjects. One must be cognizant of this effect when designing studies of odor-stimulated functional MR imaging.
年龄、性别和利手对嗅觉的影响尚未在气味刺激功能磁共振成像研究中得到充分探讨。我们试图确定年龄对气味刺激功能磁共振成像实验的影响。
5名平均年龄73岁的右利手受试者和5名平均年龄24岁的右利手受试者接受了使用双侧嗅觉刺激的梯度回波平面功能磁共振成像检查。成像参数包括3000/30（TR/TE），在一个6分钟的序列中，层厚为5毫米，30秒的脉冲气味剂与30秒的室内空气交替出现。数据被归一化到一个标准图谱，并为每个任务生成个体和组的统计参数图（SPM）。将SPM阈值设定为P < .01，比较两组的激活体积和簇最大值的分布。
对组SPM的分析显示，额叶、外侧裂周围区域和扣带回有激活的体素，年轻组的激活体积大于老年组。右侧额下回、右侧外侧裂周围区域以及右侧和左侧扣带束激活的体素数量最多。两组个体图谱上最常见的激活部位是右侧额下回区域以及右侧和左侧额上回及外侧裂周围区域。
在类似的嗅觉任务范式下，年轻受试者比老年受试者表现出更多的激活体素。在设计气味刺激功能磁共振成像研究时必须认识到这种影响。
