Simon-Zoula Sonia C, Boesch Chris, De Keyzer Frederik, Thoeny Harriet C
Institute of Diagnostic, Interventional and Pediatric Radiology, University and Inselspital, Bern, Switzerland.
J Magn Reson Imaging. 2008 Jan;27(1):43-8. doi: 10.1002/jmri.21071.
To evaluate the function of the parotid glands before and during gustatory stimulation, using an intrinsic susceptibility-weighted MRI method (blood oxygenation level dependent, BOLD-MRI) at 1.5T and 3T.
A total of 10 and 13 volunteers were investigated at 1.5T and 3T, respectively. Measurements were performed before and during gustatory stimulation using ascorbate. Circular regions of interest (ROIs) were delineated in the left and right parotid glands, and in the masseter muscle for comparison. The effects of stimulation were evaluated by calculating the difference between the relaxation rates, DeltaR(2)*. Baseline and stimulation were statistically compared (Student's t-tests), merging both parotid glands.
The averaged DeltaR(2)* values prestimulation obtained in all parotid glands were stable (-0.61 to 0.38 x 10(-3) seconds(-1)). At 3T, these values were characterized by an initial drop (to -2.7 x 10(-3) seconds(-1)) followed by a progressive increase toward the baseline. No significant difference was observed between baseline and parotid gland stimulation at 1.5T, neither for the masseter muscle at both field strengths. A considerable interindividual variability (over 76%) was noticed at both magnetic fields.
BOLD-MRI at 3T was able to detect DeltaR(2)* changes in the parotid glands during gustatory stimulation, consistent with an increase in oxygen consumption during saliva production.
采用1.5T和3T场强下的固有磁化率加权磁共振成像方法（血氧水平依赖性功能磁共振成像，BOLD-MRI）评估味觉刺激前后腮腺的功能。
分别对10名和13名志愿者在1.5T和3T场强下进行研究。在使用抗坏血酸进行味觉刺激前后进行测量。在左右腮腺以及咬肌中划定圆形感兴趣区（ROI）用于比较。通过计算弛豫率之差DeltaR(2)*来评估刺激效果。对双侧腮腺合并后的基线值和刺激值进行统计学比较（Student t检验）。
所有腮腺在刺激前获得的平均DeltaR(2)*值稳定（-0.61至0.38×10⁻³秒⁻¹）。在3T场强下，这些值的特征是先下降（至-2.7×10⁻³秒⁻¹），随后逐渐向基线值升高。在1.5T场强下，腮腺刺激前后以及在两个场强下咬肌的刺激前后均未观察到显著差异。在两个磁场下均观察到相当大的个体间差异（超过76%）。
3T场强下的BOLD-MRI能够检测到味觉刺激期间腮腺的DeltaR(2)*变化，这与唾液分泌过程中氧消耗增加一致。
