多模态MRI对肺良恶性病变诊断的价值

Value of Multimodal MRI in Differential Diagnosis of Benign and Malignant Pulmonary Lesions

目的研究多模态MRI在肺良恶性病变诊断中的价值。方法前瞻性搜集肺占位病变者81例,排除1例心脏搏动伪影及3例无法测出ADC值,最终纳入具有完整MRI图像病例77例。术前采用Philips 1.5 T MRI完成胸部常规序列、DWI和动态增强序列。所有病例分别测量b=600 s/mm^2和b=800 s/mm^2时病变区的ADC值,动态强化曲线根据Schaefer分型分为4种类型,比较不同序列联合应用诊断肺部恶性病变的敏感性、特异性及准确性,并采用配对卡方检验分析不同组的诊断效能。结果肺部良恶性病变的ADC值和DCE曲线有差异,恶性病变以A、B型曲线为主,b=600 s/mm^2时,良恶性病变平均ADC值分别为1.61×10^(-3)mm^2/s和1.27×10^(-3)mm^2/s;b=800 s/mm^2时,良恶性病变平均ADC值为1.46×10^(-3)mm^2/s和1.14×10^(-3)mm^2/s。且b=600 s/mm^2时诊断效能最高。常规MRI联合DCE及DWI诊断恶性病变的效能高于DCE组和DWI组,其敏感性、特异性和准确性分别为94.1%、88.5%和92.2%。结论 DCE联合DWI对良、恶性肺部病变的鉴别诊断有意义,可作为无典型形态学特征病变的重要补充。

Objective To evaluate the multimodal MRI findings and use the to define the benignity or malignity of pulmonary lesions. Methods 81 consecutive patients with pulmonary lesions were included in this prospective study. On account of artifacts and signal intensity disparities,4 cases were excluded and 77 cases were ultimately selected. Philips 1. 5Tesla MRI was used for standard MR examinations including routine sequence of DCE and DWI. Regions of interest（ ROIs） were drawn on the lesions on DWI images and the apparent diffusion coefficient（ ADC） was calculated with different b values（ b = 600 s / mm2 and b = 800 s / mm2）. The DCE curve types were classified into four categories. The sensitivity,specificity and accuracy in the diagnosis of malignant lesions was also be calculated. McN emar tests were used to evaluate the diagnostic value. Results The ADC value and curve types were different between benign and malignant lesions.When b = 600 s / mm2,benign lesions had ADC value of 1. 61 × 10-3mm2/ s and 1. 27 × 10-3mm2/ s in malignant lesions.When b = 800 s / mm2,benign lesions had ADC value of 1. 46 × 10-3mm2/ s and 1. 14 × 10-3mm2/ s in malignant lesions.Diagnostic accuracy was the most reliable when the b value at 600 s / mm2. A combination of DCE and DWI had a sensitivity of 94. 1%,a specificity of 88. 5% and an accuracy of 92. 2%,better than individual DCE and DWI groups. Conclusion The combined application of DCE and DWI can improve the accuracy of diagnosis of malignant pulmonary lesions and it can represent an important new additional sequence when there is no typical morphology.