量化MRI对良恶性甲状腺结节的定性诊断与超声对比分析

Analysis of quantitative MRI and ultrasound in qualitative diagnosis of benign and malignant thyroid nodules

目的探讨良恶性甲状腺结节在量化磁共振成像中的ADC值,FS-T_2WI信号强度比(SIR)阈值及超声的影像特征,对比分析其对甲状腺结节定性的诊断价值。方法观察20例经临床确诊的甲状腺结节患者共28个病灶,其中良性结节14个,恶性结节14个,术前均经超声、磁共振T1WI、FS-T_2WI及弥散加权成像(b值取0、300s/mm2)检查。计算T_2WI信号强度比(SIR);统计出良恶性结节的表观弥散系数(ADC)阈值范围。通过T_2WI信号强度比(SIR)、ADC值及结节在常规磁共振中的影像学特征确定磁共振对良恶性结节的最佳诊断标准,并与超声对结节定性诊断的结果进行比较。分析磁共振及超声对鉴别甲状腺结节良恶性的诊断价值。结果良性结节的平均T_2WI信号强度比(P<0.05)和ADC(P<0.05)值均显著高于恶性结节。T_2SIR的诊断灵敏度,特异度分别为100%,85.71%;ADC值的诊断灵敏度,特异度分别100%,84.62%;在T_2SIR和ADC联合诊断中的灵敏度,特异度分别为100%,92.86%。超声在甲状腺良恶性结节诊断中的灵敏度,特异度分别为92.86%,64.29%。结论磁共振及超声对甲状腺结节的良恶性判断均具有一定的优势,磁共振扫描中应用FS-T_2WI信号强度比(SIR)、ADC值定量诊断对结节的性质鉴别更加准确。

Objective To investigate the value of ADC, FS-T2WI signal intensity ratio （SIR） threshold in the quantized magnetic resonance imaging and ultrasound imaging characteristics of benign and malignant thyroid nodules. To compare and analyze the diagnostic value of the qualitative diagnosis of thyroid nodules. Method This study included 20 patients clinically diagnosed with thyroid nodules. A total of 28 solid thyroid nodules, including 14 benign nodules and 14 malignant nodules. All were examined by ultrasound, magnetic resonance T1WI, FS-T2WI and diffusion weighted imaging （b value 0,300 s/mm^2）. The T2 signal intensity ratio （SIR） of each thyroid nodule was calculated. The threshold range of apparent diffusion coefficient （ADC） of benign and malignant nodules. The T2WI signal intensity ratio （SIR）, ADC value and nodules on conventional magnetic resonance imaging features in determining the best diagnostic criteria for magnetic resonance imaging of benign and malignant nodules, and compared with the results of ultrasound in qualitative diagnosis of nodules. To analyze the value of magnetic resonance imaging and ul- trasound in the diagnosis of benign and malignant thyroid nodules. Results The mean T2 SIR （ P 〈 0.05 ） and ADC （ P 〈 0. 05） were significantly higher for benign nodules than for Malignant nodule. The sensitivity and specificity was 100% and 85.71%, on T2 SIR; were 100%, 84.62%, on ADC; were 100%, 92.86% ,on combined T2SIR and ADC. The sensitivity and specificity of ultrasound in the diagnosis of benign and malignant thyroid nodules were 92.86% and 64.29%, respectively. Conclusion Magnetic resonance imaging and ultrasound have certain advantages in the diagnosis of benign and malignant thyroid nodules. FS-T2WI signal intensity ratio （SIR） and ADC value in the diagnosis of benign and malignant thyroid nodules were more accurate in magnetic resonance imaging.