周围型肺癌的磁共振体素内不相干运动扩散加权成像

目的 探讨磁共振体素内不相干运动扩散加权成像(IVIM-DWI)在周围型肺癌的可行性及诊断价值。方法 收集CT发现肺部孤立性病变的患者38例,周围型肺癌30例,感染性肉芽肿8例。其中35例经病理证实,3例经临床资料证实。所有患者术前或治疗前均接受IVIM-DWI,b值为0、25、50、75、100、200、400、600、800、1000 s/mm²,分别测量所有病灶的真实扩散系数(D)、灌注相关扩散系数(D^*)及灌注分数(f)值并进行统计学分析。31例行CD34染色并计数微血管密度(MVD),并将D、D^*及f值与MVD进行相关性分析。结果 周围型肺癌的f值(29.29±10.89)%]明显低于感染性肉芽肿(46.10±12.92)%,P<0.01)];周围型肺癌D值、D^*值与感染性肉芽肿差异无统计学意义(P均>0.05)。周围型肺癌和感染性肉芽肿的D值、D^*值、f值与MVD计数均无明显相关性(P均>0.05)。f值的ROC曲线下面积为0.83,最佳阈值为38.00%,诊断周围型肺癌的敏感度为0.80,特异度为0.75。结论 IVIM-DWI技术可用于检查肺部孤立性病变,f值在周围型肺癌及感染性肉芽肿的鉴别诊断方面具有一定价值。

MR intravoxel incoherent motion diffusion-weighted imaging in peripheral lung cancer

Objective To explore possibility and diagnostic value of the MR intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in the peripheral lung cancer. Methods Thirty-eight patients (30 cases of peripheral lung cancer, 8 cases of infectious granuloma) with pulmonary isolated lesions were found by CT, and 35 cases were confirmed by pathology and 3 cases were confirmed by clinics. All cases were examined with IVIM-DWI sequence before operation or treatment. b-values was 0, 25, 50, 75, 100, 200, 400, 600, 800, 1000 s/mm² respectively. The parameters of diffusion coefficient (D), diffusion coefficient from the perfused compartment (D^*) and perfusion fraction (f) of all lesions was calculated; 31 cases were stained by CD34 and counted micro-vessel density (MVD), then correlation between D, D^*, f and MVD were analyzed. Results The value of f was significantly lower in peripheral lung cancer (29.29±10.89]%) comparing with infectious granuloma (46.10±12.92]%, P<0.01). There was no significant difference between peripheral lung cancer and infectious granuloma for D and D^* (P>0.05). The values of D, D^*, f and MVD of peripheral lung cancer and infectious granuloma were not significantly correlated (all P>0.05). The area under the ROC of the f values was 0.83, the cut-off of f values was 38.00%, the sensitivity and specificity in diagnosis of peripheral lung cancer was 0.80, 0.75 respectively. Conclusion IVIM-DWI is reliable in pulmonary isolated lesions. f is helpful in distinguishing peripheral lung cancer from infectious granuloma.