Department of Electrical Engineering and Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, No. 1, Sec 4, Roosevelt Road, MD-624, Taipei, Taiwan.
Radiology. 2013 Jun;267(3):918-23. doi: 10.1148/radiol.12112599. Epub 2013 Jan 17.
To evaluate the effectiveness of three fat measurement methods for parotid glands in healthy subjects, with or without metallic dental implants.
The institutional review board approved this study, with informed consent obtained from 114 volunteers undergoing magnetic resonance (MR) imaging at 1.5 T. Fat-saturated (FS) and non-fat-saturated (NFS) fast spin-echo T1-weighted imaging (T1 method), FS and NFS T2-weighted periodically rotated overlapping parallel lines with enhanced reconstruction fast spin-echo imaging (T2 method), and gradient-echo imaging with fat-water separation using iterative decomposition with echo asymmetry and least squares (IDEAL) method were used to derive parotid fat contents. Two raters examined the homogeneity of fat saturation to determine whether parotid fat quantification was successful, with the success rate in the 114 subjects recorded for each protocol. In subjects whose fat quantification was successful with all three imaging methods, linear regression was used to analyze the correlation between any pair of the three parotid fat content measurement methods.
Success rates in parotid fat measurements by using T1, T2, and IDEAL methods were 87.7% (100 of 114), 87.7% (100 of 114), and 100% (114 of 114), respectively. The means of measured parotid fat contents revealed significant differences (P < .001) between any pair of the three measurement methods. The parotid fat contents measured with the three methods were significantly correlated with each other between any pair of combinations.
The IDEAL method provided a high success rate for parotid fat measurements, even in subjects with metallic dental implants.
评估三种脂肪测量方法在健康受试者（包括有无金属牙种植体）腮腺中的有效性。
本研究经机构审查委员会批准，114 名志愿者在 1.5T 磁共振（MR）成像时签署了知情同意书。对所有志愿者分别采用脂肪饱和（FS）和非脂肪饱和（NFS）快速自旋回波 T1 加权成像（T1 方法）、FS 和 NFS 周期性旋转重叠并行线增强重建快速自旋回波成像（T2 方法）、以及使用迭代分解的带有回波不对称和最小二乘法的梯度回波成像（IDEAL 方法）来测量腮腺脂肪含量。两名评估者检查了脂肪饱和的均匀性，以确定腮腺脂肪定量是否成功，并记录了每种方案在 114 名受试者中的成功率。在三种成像方法均成功定量腮腺脂肪的受试者中，采用线性回归分析三种腮腺脂肪含量测量方法中任意两种之间的相关性。
采用 T1、T2 和 IDEAL 方法测量腮腺脂肪的成功率分别为 87.7%（114 例中的 100 例）、87.7%（114 例中的 100 例）和 100%（114 例中的 114 例）。任意两种方法测量的腮腺脂肪含量均值之间存在显著差异（P＜0.001）。三种方法测量的腮腺脂肪含量之间在任意两种组合之间均存在显著相关性。
即使在有金属牙种植体的受试者中，IDEAL 方法也能为腮腺脂肪测量提供较高的成功率。
