磁共振DWI对肺内孤立性病变鉴别诊断价值

The Value of Diffusion-Weighted MR Imaging for Differentiation of Solitary Pulmonary Lesions

目的评价MRI扩散加权成像(DWI)对肺内孤立性病变的鉴别诊断价值。方法搜集经手术、活检或临床治疗随访后证实的56例肺内孤立性病变患者,其中恶性35例,良性21例,行MRI胸部常规T_1WI、T_2WI和DWI检查,b值选择300,500,800和1000 s/mm^2。分别测量不同b值时的表观扩散系数(ADC)和病变脊髓比值(LSR)。计算不同b值时受试者工作特征(ROC)曲线下ADC和LSR面积。结果良、恶性肺内孤立性病变在b值300～800 s/mm^2时,其ADC值有统计学意义(t=2.07,P_(300)=0.04<0.05;t=4.68,P_(500)=0.000;t=3.32,P_(800)=0.03<0.05);ROC曲线下面积分别为0.72、0.88、0.66、0.54。而b值在300～1000 s/mm^2时,其LSR值均有统计学意义(P_(300～1000)<0.001),ROC曲线下面积分别为0.98、0.93、0.92、0.93。结论 DWI的ADC和LSR值可以实现良、恶性肺内孤立性病变定量分析;LSR值的鉴别诊断效能优于ADC值,更有实用性。

Objective To evaluate the value of diffusion-weighted imaging(DWI)for distinguishing solitary pulmonary lesions by magnetic resonance imaging.Methods 56 patients with solitary pulmonary lesions(malignant in 35 and benign in 21)who were confirmed by operation,biopsy and clinical follow up after treatment,underwent routine chest T1WI,T2WI and DWI.The b values were chosen as 300,500,800 and 1000 s/mm2.and the corresponding apparent diffusion coefficient(ADC)and lesion-to-spinal cord ratio(LSR)were respectively measured.The area of ADC and LSR were calculated under Receiver operating characteristics(ROC)curve at different b values.Results The ADC value between benign and malignant pulmonary lesions was statistically significant with b values from 300 to 800 s/mm2(t=2.07,P300=0.04<0.05;t=4.68,P500=0.000;t=3.32,P800=0.03<0.05),the area under ROC curve was 0.72、0.88、0.66 and 0.54 respectively,meanwhile the LSR value was all statistically significant with b values from 300 to 1000 s/mm2(P300-1000<0.001))and the area under ROC curve was 0.98、0.93、0.92 and 0.93 respectively.Conclusion The ADC and LSR value of DWI can be used for quantitative analysis in benign and malignant solitary pulmonary lesions;the differential diagnostic efficiency of LSR value is superior to ADC value and more practical.