嗅覺功能性核磁共振造影－初步報告

Olfactory Functional Magnetic Resonance Imaging-A Preliminary Report

江榮山(Rong-San Jiang) ； 郭泰鑫(Tai-Shin Guo) ； 梁凱莉(Kai-Li Liang) ； 江志明(Chih-Ming Chiang) ； 蔡志文(Jyh-Wen Chai) ； 陳啟昌(Clayton Chi-Chang Chen) ； 蘇茂昌(Mao-Chang Su) ； 辛宗翰(Chung-Han Hsin)

《台灣耳鼻喉頭頸外科雜誌》 42卷1期 (2007/02) Pp. 6-11

https://doi.org/10.6286/2007.42.1.6

摘要

BACKGROUND: Functional magnetic imaging (fMRI) is an important approach to the study of brain function; the method can observe cortical activity non-invasively during the performance of a task. Up to the present, fMRI has been widely used to study brain function related to the different sensory systems. However, no studies in Taiwan have reported the use of fMRI to study the olfactory system.
METHOD: In this study, the odor presentation involved the use of a continuous positive airway pressure device that supplies a main air stream; then compressed air controlled by a flowmeter was used to release odorants into the main air stream. By means of a pneumatic three-way valve-switching device, an odor or non-odor condition could be chosen. The olfactory stimuli consisted of a pleasant odor (phenyl ethyl alcohol) and an unpleasant odor (acetic acid). Each test was composed of four blocks of olfactory stimulus. Each block was sustained for 10 seconds, and the interval between the blocks was 20 seconds. Subjects were also asked to sniff every three second. Blood oxygenation level-dependent fMRI was acquired using a 1.5 Tesla Siemens Sonota system. A T2(superscript *)-weighted echo planar imaging sequence (TR=2000 ms; TE=60 ms; =90o; matrix 128×128; FoV=240×240 mm; slice thickness=4 mm; distance factor 0.2; pixel size=1.875×1.875 mm) was applied.
RESULT: Nine volunteers with normal olfactory function took part in the study between August, 2005 and April, 2006 and these volunteers consisted of four men and five women with an age range from 20 to 56 years old. Significant activation was induced only in some areas of the secondary olfactory cortex-orbitofrontal cortex. Activation by the pleasant odor was primarily in the right brain, while activation by the unpleasant odor was primarily in the left brain.
CONCLUSION: Significant activation was induced only in some areas of the secondary olfactory cortex in this study and further investigation need to be carried out involving modification of the present procedures in order to increase activation.

關鍵字

連續性正呼吸道壓力 ； 功能性磁振造影 ； 嗅覺皮質 ； 嗅覺刺激

並列摘要

BACKGROUND: Functional magnetic imaging (fMRI) is an important approach to the study of brain function; the method can observe cortical activity non-invasively during the performance of a task. Up to the present, fMRI has been widely used to study brain function related to the different sensory systems. However, no studies in Taiwan have reported the use of fMRI to study the olfactory system.
METHOD: In this study, the odor presentation involved the use of a continuous positive airway pressure device that supplies a main air stream; then compressed air controlled by a flowmeter was used to release odorants into the main air stream. By means of a pneumatic three-way valve-switching device, an odor or non-odor condition could be chosen. The olfactory stimuli consisted of a pleasant odor (phenyl ethyl alcohol) and an unpleasant odor (acetic acid). Each test was composed of four blocks of olfactory stimulus. Each block was sustained for 10 seconds, and the interval between the blocks was 20 seconds. Subjects were also asked to sniff every three second. Blood oxygenation level-dependent fMRI was acquired using a 1.5 Tesla Siemens Sonota system. A T2(superscript *)-weighted echo planar imaging sequence (TR=2000 ms; TE=60 ms; =90o; matrix 128×128; FoV=240×240 mm; slice thickness=4 mm; distance factor 0.2; pixel size=1.875×1.875 mm) was applied.
RESULT: Nine volunteers with normal olfactory function took part in the study between August, 2005 and April, 2006 and these volunteers consisted of four men and five women with an age range from 20 to 56 years old. Significant activation was induced only in some areas of the secondary olfactory cortex-orbitofrontal cortex. Activation by the pleasant odor was primarily in the right brain, while activation by the unpleasant odor was primarily in the left brain.
CONCLUSION: Significant activation was induced only in some areas of the secondary olfactory cortex in this study and further investigation need to be carried out involving modification of the present procedures in order to increase activation.

並列關鍵字

continuous positive airway pressure ； fMRI ； olfactory cortex ； olfactory stimulus