DWI-MRI对区分中央型肺癌与阻塞性肺不张的价值

DWI-MRI in distinguishing central lung cancer from obstructive atelectasis

目的通过磁共振扩散加权成像(DWI)、T2WI、T1WI各序列和增强CT的比较,探讨DWI对于区分中央型肺癌与阻塞性肺不张的价值。方法对2015年3月至2017年12月收治的48例中央型肺癌合并阻塞性肺不张的患者行胸部MRI及增强CT扫描,MRI扫描序列包括:T1WI-Vibe、T2WI-HASTE、DWI(b=50,800 s/mm2)。分析中央型肺癌合并肺不张的MRI各序列信号特点和增强CT表现,测量DWI和T2WI的信号强度、计算图像的对比噪声比,并测量肿瘤与肺不张的ADC值。结果48例图像均能满足诊断需要。DWI对肿瘤与肺不张的区分能力明显高于T1WI及CT增强(P<0.01)。DWI与T2WI序列的区分能力无统计学差异(P>0.05)。DWI联合T2WI能对43例肿瘤与肺不张进行区分,区分能力高于T2WI(P<0.01),亦高于DWI单独使用,但差异无统计学意义(P>0.05);DWI图像的对比噪声比高于T2WI,瘤体的DWI信号强度高于肺不张,瘤体的ADC值低于肺不张(P<0.01)。结论通过评价DWI信号特点和ADC值的测量,DWI联合T2WI序列有助于中央型肺癌肿瘤与阻塞性肺不张的区分。

Objective To investigate the value of diffusion weighted imaging magnetic resonance imaging(DWI-MRI),T1-weighted images(T1WI),T2-weighted images(T2WI)and contrast-enhanced CT in differentiating central lung cancer from obstructive atelectasis.Methods From March 2015 to December 2017,48 patients with central lung cancer complicated with obstructive pulmonary atelectasis underwent chest MRI[including T1WI-Vibe,T2WI-HASTE and DWI(b=50,800 s/mm)]and enhanced CT scanning.The signal intensity of DWI and T2WI,contrast-to-noise ratio(CNR)and apparent diffusion coefficient(ADC)value were measured to analyze the characteristics of MRI sequences and enhanced CT scanning of central lung cancer with atelectasis.Results All images met the needs of diagnosis in 48 patients.The differentiation ability of DWI was significantly superior to that of T1WI and contrast-enhanced CT in distinguishing tumor from atelectasis(P<0.01),and there was no significant difference in it between DWI and T2WI(P>0.05).The differentiation ability of DWI combined with T2WI was statistically better than that of T2WI(P<0.01)and was slightly higher than that of DWI alone(P>0.05).CNR of DWI was higher than that of T2WI,and the mean signal intensity of tumors was higher than that of atelectasis on DWI images(P<0.01).Mean ADC value of tumor was significantly lower than that of atelectasis(P<0.01).Conclusion Through the evaluation of DWI signal characteristics and ADC value measurement,DWI combined with T2WI sequence is helpful to distinguish central lung cancer from obstructive pulmonary atelectasis.