泪腺磁化传递成像定量参数在甲状腺相关性眼病临床活动性分期中的价值

The value of quantitative parameters on magnetization transfer imaging of lacrimal glands in distinguishing the clinical activity of thyroid-associated ophthalmopathy

目的 探讨泪腺磁化传递成像(magnetization transfer imaging, MTI)定量参数在甲状腺相关性眼病(thyroid-associated ophthalmopathy, TAO)临床活动性分期中的价值。材料与方法 前瞻性纳入2020年9月至2022年1月在南京医科大学第一附属医院临床诊断为TAO的49名患者,依据临床活动性评分(Clinical Active Score, CAS)将受试者分为活动期组(≥3分,29例)和非活动期组(<3分,20例)。所有受试者均行眼眶常规MRI序列及冠状位MTI扫描,并测量泪腺磁化传递率(magnetization transfer ratio, MTR)及脂肪抑制T2WI序列上泪腺与同侧颞肌信号强度比(signal intensity ratio, SIR)。采用Mann-Whitney U检验比较MRI定量参数的组间差异。采用Spearman相关分析评估MRI定量参数与CAS的相关性。采用受试者工作特征曲线分析MTR、SIR及两者联合判断TAO临床活动性的效能,并采用DeLong检验比较曲线下面积(area under the curve, AUC)。结果 活动期组泪腺MTR低于非活动期组,泪腺SIR高于非活动期组,差异均有统计学意义(P<0.001)。MTR与CAS呈低度负相关(r=-0.427,P<0.001),SIR与CAS呈弱正相关(r=0.252,P=0.012)。联合泪腺MTR和SIR判断TAO临床活动性效能最优(AUC=0.809,敏感度62.5%,特异度93.1%),高于单独应用SIR,差异有统计学意义(Z=2.35,P=0.019)。结论 泪腺MTI定量参数在判断TAO临床活动性中具有可行性,可以作为常规序列的补充手段,以提高对TAO临床活动性分期的评估能力。

Objective: To investigate the value of quantitative parameters on magnetization transfer imaging(MTI) of lacrimal gland in distinguishing the clinical activity of thyroid-associated ophthalmopathy(TAO). Materials and Methods: From September 2020 to January 2022, we prospectively recruited 49 TAO patients in the First Affiliated Hospital of Nanjing Medical University, and divided them into active groups(≥3 points, 29 patients) and inactive group(<3 points, 20 patients) according to the Clinical Activity Score(CAS). All subjects underwent conventional MRI and coronal MTI scan of the orbit. Magnetization transmissibility ratio(MTR) of lacrimal glands and the signal intensity ratio(SIR) on fat suppression-T2WI between lacrimal glands and temporalis were measured,respectively. Mann-Whitney U test was applied to compare the differences of MRI quantitative parameters between two groups. The correlations between MRI parameters and CAS were evaluated using Spearman correlation analysis. Receiver operating characteristic curve analysis was used to assess the predictive value of each quantitative parameter in judging the clinical activity of TAO, and the area under the curves(AUC) were compared using the DeLong test. Results: The MTRs of lacrimal glands in active group were significantly lower than those in inactive group(P<0.001), while the SIRs of lacrimal glands in active group were significantly higher than those in inactive group(P<0.001). MTR was mildly and negatively correlated with CAS(r=-0.427, P<0.001), while SIR was weakly and positively correlated with CAS(r=0.252, P=0.012). The combination of MTR and SIR showed the optimal diagnostic performance in distinguishing the clinical activity of TAO(AUC=0.809, sensitivity 62.5%, specificity 93.1%), which was better than SIR alone, and the difference was statistically significant(Z=2.35, P=0.019). Conclusions: The quantitative parameters on MTI of lacrimal glands are feasible in distinguishing clinical activity of TAO, which can be used as a supplement to conventional MRI sequences to improve the performance in evaluating the clinical activity of TAO.