体素内不相干运动在甲状腺良恶性结节中的诊断价值

Differentiation of Benign and Malignant Thyroid Nodules Using Intravoxel Incoherent Motion

目的甲状腺结节良恶性诊断至关重要,本研究拟探讨体素内不相干运动(IVIM)在甲状腺良恶性结节中的诊断价值。资料与方法经手术病理确诊的45例甲状腺结节患者共56个结节,术前均行常规MRI检查和IVIM序列扫描。比较甲状腺良恶性结节标准表观扩散系数(ADC_(标准))、慢速ADC(ADC_(慢速))、快速ADC(ADC_(快速))、快速ADC分数值(F_(快速));采用受试者操作特征(ROC)曲线确定诊断阈值,评估上述参数对甲状腺良恶性结节的诊断效能。结果甲状腺恶性结节组ADC_(标准)、ADC_(慢速)、ADC_(快速)值低于良性结节组,而F_(快速)值高于良性结节组,差异均有统计学意义(t=3.928、3.827、4.569、5.309,P<0.001);甲状腺恶性结节组F_(快速)的ROC曲线下面积最大,为0.841,诊断阈值为32.04%,其敏感度、特异度、准确度分别为93.8%、70.0%和76.7%。结论 IVIM序列各参数鉴别甲状腺良恶性结节有一定的价值,其中F_(快速)值对甲状腺恶性结节的诊断效能最大。

Purpose The preoperative diagnosis of thyroid nodules is critical for guiding therapeutic strategies, this study is to preliminary investigate the application value of intravoxel incoherent motion（IVIM） in the differential diagnosis of benign and malignant thyroid nodules. Materials and Methods Forty-five patients with fifty-six thyroid nodules underwent routine MRI sequences and IVIM sequence before operation. The standard ADC（ADCstandard）, slow ADC（ADCslow）, fast ADC（ADCfast） and fraction of fast ADC（Ffast） value of benign and malignant thyroid nodules were compared. Diagnostic threshold and efficacy for the differentiation of benign and malignant thyroid nodules of these parameters were evaluated by using receiver operating characteristic（ROC） curve. Results The ADCstandard, ADCslow and ADCfast of malignant thyroid nodule group were lower than those of benign nodule group, while Ffast value was higher than that of the benign nodule group, and the differences were all statistically significant（t=3.928, 3.827, 4.569 and 5.309, P〈0.001）; the area under the curve of Ffast was the maximum, which was 0.841, the diagnostic threshold was 32.04%, the sensitivity, specificity and accuracy was 93.8%, 70.0% and 76.7%, respectively. Conclusion The parameters of IVIM were valuable for differentiating benign and malignant thyroid nodules, and the most valuable parameter for differentiating malignant thyroid nodules was Ffast.