Small Peripheral Lung Cancer Evaluated with MR imaging : Correlation with Pathologic Findings, Vascular Endothelial Growth Factor, and Prognosis

目的：探讨周围型小肺癌增强动态磁共振成像表现与肿瘤血管及预后的关系。材料与方法：对94例手术切除的周围型小肺癌进行回顾性分析。病理标本行苏木精-伊红和弹性蛋白-van Gieson染色。免疫组织化学方法检测CD34和血管内皮生长因子(VEGF)的表达。CD34阳性细胞计数为微血管。动态磁共振成像在注射吉多喷妥钠地葡胺前和注射后1、2、3、4、5、6和8分钟进行。两名观察者检查了所有的图像，两名病理学家进行了所有的组织学分析；一致同意做出了决定。最大增强率(MER)、注射完成至最大信号强度点的时间间隔(Tmax)、时间-信号强度曲线的冲洗率和斜率与微血管密度相关。比较血管内皮生长因子阳性和阴性的肿瘤。结果：MER与斜率呈正相关，Tmax与微血管计数呈负相关(Spearman等级检验，P&lt；.0001，均为比较)。弹性纤维和胶原纤维的分布与洗脱率相关(Kruskal-Wallis检验，P&lt；.001)。VEGF阳性肿瘤与VEGF阴性肿瘤的斜率差异有统计学意义(Mann-Whitney U检验，P&lt；0.0001)。血管内皮生长因子阳性肿瘤患者的总生存期明显短于血管内皮生长因子阴性肿瘤患者(log-ranch检验，P&lt；.0001)。结论：动态磁共振成像表现与肿瘤的血管密度有关，有助于预测预后。

PURPOSE : To correlate the findings at contrast material-enhanced dynamic magnetic resonance (MR) imaging of small peripheral pulmonary carcinomas, 3-cm and smaller in the largest diameter, with tumor vascularity and prognosis.MATERIALS AND METHODS : Ninety-four patients with small peripheral pulmonary carcinomas who underwent surgical resection were examined retrospectively. Pathologic specimens were stained with hematoxylin-eosin and elastin-van Gieson. CD34 and vascular endothelial growth factor (VEGF) were assessed immunohistochemically. Delineated CD34-positive cells were counted as microvessels. Dynamic MR imaging was performed prior to and at 1, 2, 3, 4, 5, 6, and 8 minutes after injection of a bolus of gadopentetate dimeglumine. The two observers reviewed all images, and two pathologists performed all histologic analyses; a decision was determined with consensus. The maximum enhancement ratio (MER), the time lapse between the completion of the injection and the point of maximum signal intensity (Tmax), the washout ratio, and the slope value of the time-signal intensity curve were correlated with the microvessel density. VEGF-positive and VEGF-negative tumors were compared. All statistical analyses were performed by using nonparametric methods.RESULTS : The MER and the slope value were positively correlated, and the Tmax was negatively correlated (Spearman rank test, P<.0001, all comparisons) with the microvessel counts. The distribution of elastic and collagen fibers correlated with the washout ratio (Kruskal-Wallis test, P<.001). There was a statistically significant difference between the slope value of VEGF-positive tumors and that of VEGFnegative tumors (Mann-Whitney U test, P<.0001). Patients with VEGF-positive tumors had a significantly shorter overall survival than did those with VEGF-negative tumors (log-rank test, P<.0001).CONCLUSION : Dynamic MR imaging findings correlate with tumor vascularity and may be helpful in the prediction of prognosis.