Liu Yi-Jui, Lee Yi-Hsiung, Chang Hing-Chiu, Chiu Hui-Chu, Chiu Ta-Wei, Hsu Kang, Pen Cheng-Ming, Hsu Hsian-He, Juan Chun-Jung
Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, Republic of China.
PhD Program in Electrical and Communication Engineering, Feng Chia University, Taichung, Taiwan, Republic of China.
NMR Biomed. 2018 Mar;31(3). doi: 10.1002/nbm.3885. Epub 2018 Jan 8.
The aim of this study was to investigate proton changes of the parotid gland after gustatory stimulation by semi-quantitative parameters and an empirical mathematical model (EMM) using high-temporal-resolution, double-echo, echo-planar imaging (EPI). Approved by a local institutional review board, this study examined 20 parotid glands from 10 healthy volunteers (male:female = 6: 4; age ± standard deviation =35.1 ± 14.1 years) with written informed consent obtained. All participants underwent 1.5-T, double-echo EPI with gustatory stimulation. Semi-quantitative parameters, including maximal drop ratio (MDR), time to peak (TTP), drop slope (DS), recovery slope (RS) and recovery ratio (RR), were calculated. The effect of temporal resolution on parotid functional parameters was evaluated. An EMM comprising an output function ( Sot=Aoe-kot+B) and an input function ( Sint=Ain1-e-kint) was also applied to fit all dynamic curves. Kruskal-Wallis test, Wilcoxon test, linear regression analysis and goodness of fit were used for statistical analysis. p < 0.05 was considered to be statistically significant. The signal intensity dropped significantly after gustatory stimulation on the proton density (PD) image (p < 0.01). MDR was 8.26% in the PD image. MDR and RR were negatively associated with time interval, whereas DS and TTP were significantly positively associated with time interval (all p < 0.05). EMM parametric values derived from PD-time curves of parotid glands were 12.04 ± 6.81%, 6.43 ± 4.23 min , 88.73 ± 6.18%, 8.41 ± 4.86 min and 1.09 ± 1.35 for A , k , B, A and k , respectively. Semi-quantitative functional parameters and EMM parameters using high-temporal-resolution, double-echo EPI allow the quantification of parotid proton changes after gustatory stimulation.
本研究旨在通过半定量参数和经验数学模型（EMM），利用高时间分辨率、双回波、回波平面成像（EPI）研究味觉刺激后腮腺的质子变化。本研究经当地机构审查委员会批准，在获得书面知情同意后，对10名健康志愿者（男∶女 = 6∶4；年龄±标准差 = 35.1±14.1岁）的20个腮腺进行了检查。所有参与者均于味觉刺激下接受1.5-T双回波EPI检查。计算了包括最大下降率（MDR）、达峰时间（TTP）、下降斜率（DS）、恢复斜率（RS）和恢复率（RR）在内的半定量参数。评估了时间分辨率对腮腺功能参数的影响。还应用了一个由输出函数（Sot = Aoe - kot + B）和输入函数（Sint = Ain1 - e - kint）组成的EMM来拟合所有动态曲线。采用Kruskal-Wallis检验、Wilcoxon检验、线性回归分析和拟合优度进行统计分析。p < 0.05被认为具有统计学意义。在质子密度（PD）图像上，味觉刺激后信号强度显著下降（p < 0.01）。PD图像上的MDR为8.26%。MDR和RR与时间间隔呈负相关，而DS和TTP与时间间隔呈显著正相关（均p < 0.05）。从腮腺的PD-时间曲线得出的EMM参数值，A、k、B、A和k分别为12.04±6.81%、6.43±4.23分钟、88.73±6.18%、8.41±4.86分钟和1.09±1.35。使用高时间分辨率、双回波EPI的半定量功能参数和EMM参数可对味觉刺激后腮腺的质子变化进行量化。
