目的 探究3.0T高场磁共振成 像(MRI)对于中央型肺癌肿块和阻塞性 改变(肺炎，阻塞性肺不张)的鉴别价 值。方法 选取85例中央型肺癌合并阻 塞性肺不张的患者进行3.0T MRI的检查 (T1WI,T2WI,DWI; b=0,400,1000s/mm2)， 同时测量与比较中央型肺癌肿块和阻 塞性改变区的表观扩散系数(apparent diffusion coefficient,ADC)值和信号 强度(signal intensity,SI)的值，并 且观察肿块和阻塞性改变在各序列的信 号特征，评级各序列对二者的鉴别能 力。结果 85例中，T1WI，T2WI，DWI和 T2WI+DWI 图像上能区分肺门肿块和阻塞 性改变者的情况分别为12例(14%)，54 例(63%)，65例(77%)和73例(86%)。经 过两两比较，T2WI、DWI鉴别肿块和阻 塞性改变的能力优于T1WI (P<0.05)； 中央型肺癌肿块和阻塞性改变的的ADC 值分别为(1.19±0.42)×10-3s/mm2、 (2.29±0.56)×10-3s/mm2；中央型肺癌 肿块于DWI的信号强度高于阻塞性改变 (P<0.05)。结论 3.0T MRI可以用于鉴别 肿块和阻塞性改变，DWI是T2W2的有效的 补充。

Objective To investigate diagnosis value of differentiating central lung cancer from obstructive atelectasis by peneumonia at 3.0T MR. Methods Eighty-five cases diagnosed to be central lung cancer with obstructive atelectasis by clinic and pathology underwent 3.0T MRI scan. Scan sequences were as followed, T1WI, T2WI and DWI(b=0,400,1000s/mm2). ADC and SI(signal intensity) of central lung cancer and collapse lung tissues were measured and compared. The differentiation ability of T1WI, T2WI and DWI were compared. Results twelve cases could be distinguished on T1WI images, fifty-four on T2WI, sixty-five on DWI, seventy-three on T2WI and DWI. The differentiation ability of T2WI and DWI was superior to that of T1WI. The mean ADC value of central lung cancer(1.18±0.43)×10-3s/mm2 was significantly lower than that of collapse lung tissues(2.28±0.57)×10-3s/mm2(P<0.05). The mean signal intensity of central lung cancer was higher than that of obstructive atelectasis and pneumonia on DWI images(P<0.05). Conclusion 3.0T MRI can be used to differentiate central lung cancer from obstructive lobar collapse. DWI is an effective complement of T2WI.