味觉刺激弥散加权成像评价正常涎腺功能

DWI evaluation of the salivary gland function during gustatory stimulation in healthy subjects

目的探测MR弥散加权成像(DWI)是否能记录味觉刺激时涎腺弥散系数(ADC)值的变化,并观察味觉刺激前后ADC值的变化。方法对17名健康志愿者行1.5TMR检查。DWI序列于静息时采集1次,给予含化维生素C片500mg之后30s至23min左右连续采集。由DWI得到刺激前后涎腺的ADC值,采用重复测量方差分析比较刺激前后的差异。结果静息状态颌下腺ADC值(1.26±0.11)×10-3mm2/s高于腮腺(1.00±0.09)×10-3mm2/s(P<0.01)。在酸刺激最初的2min(0.5～4.5min)腮腺ADC值[(1.08±0.10)×10-3mm2/s]显著升高(P<0.01),颌下腺ADC值[(1.27±0.15)×10-3mm2/s]稍升高(P=0.71);之后的7min(2.5～8.5min)腮腺ADC值[(0.09±0.01)×10-3mm2/s]和颌下腺ADC值[(1.11±0.12)×10-3mm2/s]明显下降(P<0.01);之后的9minADC值逐渐上升,至16min(10.5～22.5min)达高峰。腮腺[(1.13±0.09)×10-3mm2/s]明显高于基线值(P<0.01),颌下腺[(1.34±0.11)×10-3mm2/s]轻度提高(P=0.02)。结论DWI可以无创地评价涎腺功能变化,味觉刺激后ADC值显示出三个阶段的变化。

Objective To evaluate the function of salivary glands of healthy volunteers during gustatory stimulation with MR diffusion-weighted imaging（DWI）.Methods Seventeen healthy subjects underwent 1.5T MR examination.DWI sequence was performed once at rest and continuously repeated over a mean period of 23 min during salivary stimulation with 500 mg ascorbic acid given orally.Results At rest,ADC value of submandibular glands was higher than that of parotid glands（P〈0.01）.During the first 2 min（0.5-4.5 min）of salivary stimulation,ADC value of parotid glands increased obviously（P〈0.01）,but not the submandibular glands（P=0.71）.Then ADC was significantly decreased in both glands at 7 min（2.5-8.5 min）.During the following 9 min,a steady increase in ADC from the baseline value was noted for the parotid glands（P〈0.01）,and peak ADC appeared at 16 min（10.5-22.5 min）after the start of gustatory stimulation.ADC of the submandibular glands did not increase significantly after the start of gustatory stimulation compared with the ADC at baseline（P=0.02）.Conclusion The functional changes in the salivary glands during gustatory stimulation can be evaluated with DWI noninvasively,and DWI may contributes to the early detection of functional change of salivary glands.