口内酸刺激对主涎腺ADC值影响的初步观察

Effect of Two Different Stimulus Duration Times on The ADC Values of Major Salivary Glands

目的探讨在口内酸刺激不同保持时间下主涎腺表观扩散系数(ADC)值的变化规律及差异。方法对18名涎腺功能正常的志愿者,先于静息状态下行1次腮腺、颌下腺和舌下腺DW-MRI扫描作为基准。然后,在相邻的两天中的同一时间,向受试者口内滴注5 ml柠檬汁后采用两种不同的刺激方式:一天口内含10 s,另一天口内含2 min后吞咽,然后行扩散加权磁共振成像(DW-MRI)重复扫描各10次。两种刺激方式的先后顺序采取随机原则。分析不同保持时间组酸刺激前后主涎腺ADC值变化曲线的特点及差异,比较两组刺激后最大ADC值、刺激后最大ADC值增加率(IR)以及峰值时间(Tmax)的差别。结果两种不同刺激保持时间组各涎腺平均ADC值均在刺激后第一次扫描时(30 s)达到峰值,之后呈缓慢波动下降的单相变化趋势。柠檬汁含10 s组颌下腺Tmax为(523±415)ms,显著晚于含2 min组的(243±265)ms(t=-3.168,P=0.006)。柠檬汁含10 s组刺激后腮腺、颌下腺与舌下腺的最大ADC值分别为(1.05±0.06)×10-3mm2/s、(1.16±0.07)×10-3mm2/s与(1.11±0.06)×10-3mm2/s,均显著低于含2 min组的(1.09±0.04)×10-3mm2/s、(1.24±0.09)×10-3mm2/s与(1.28±0.18)×10-3mm2/s(腮腺t=-3.393,P=0.003;颌下腺t=-6.655,P=0.000;舌下腺t=-3.665,P=0.002)。两组刺激后各涎腺最大ADC值均显著高于刺激前(P<0.01)。柠檬汁含10 s组刺激后颌下腺最大ADC值IR为(7.94±4.53)%,显著低于含2 min组的(14.26±8.94)%(t=-4.821,P=0.000)。结论柠檬汁味觉刺激后DW-MRI可以显示刺激不同保持时间下各涎腺ADC值变化规律的差异,是评价涎腺分泌功能的合适方法之一。

Objective To explore the differences of apparent diffusion coefficients （ADCs） of the three major salivary glands under different acid stimulus duration times by using diffusion weighted MR imaging （DW MRI ）. Methods Eighteen healthy volunteers were examined with a 1.5T MR unit. A DW MRI sequence was performed once at rest and continuously repeated 10 times after two different acid stimulation ways： instilling 5 ml commercially available lemon juice in the mouth and containing for 10 s or 2 mix respectively. The subsequence of two stimulation ways was random. Characteristics and differences in ADCs curve of three salivary glands before and after stimulation between two different stimulus duration time groups were analyzed. Comparison of maximum ADCs, maximum ADCs increase rate （IR） and times to maximum ADCs （Tmax） between two groups was performed by using independent samples t test. Results Under the two stimulation ways, the mean ADCs all showed a steady increase to peak values during the first DW MRI scan after stimulation in all glands, followed by a gradually decrease fluctuating slightly around the baseline values. The mean Tmax of submandibular gland in lemon juice containing for 10 s group [ （523±415 ）ms] was significantly later than that in containing for 2 mix group [ （243±265 ）ms, t = -3.168, P = 0. 006 ]. The mean maximum ADCs of parotid glands, submandibular glands and sublingual glands in containing for 10 s group were （ 1.05 ± 0.06 ） × 10^-3 mm^2/s, （ 1. 16±0.07 ） ×10^-3 mm^2/s and （ 1.11±0.06） × 10^-3mm^2/s respectively,which were significantly lower than those of parotid glands [ （ 1.09± 0.04） ×10^-3mm^2/s, t= -3. 393 ,P =0. 003], submandibular glands [ （1.24±0.09×10^-3mm^2/s, t = -6. 655, P =0. 000] and sublingual glands [ （ 1.28±0.18） × 10^-3 mm^2/s, t = - 3. 665, P = 0. 002 ] in containing of 2 min group. The maximum ADCs after stimulation of three salivary glands in two groups were all significantly higher than those before stimulation （ P 〈 0.01 ）. The maximum ADCs IR of submandibular gland in lemon juice containing for 10 s group [ （7.94 ±4.53 ）% ] was lower than that in containing for 2 min group [ （ 14.26±8.94） %, t = - 4. 821 ,P = 0. 000 ]. Conclusion DW MRI can display the differences in ADCs of each salivary gland under two different stimulus duration times. DW MRI using lem- on juice gustatory stimulation is an appropriate method for evaluating secretory function of salivary glands.