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

目的：探讨最大直径小于3cm的小周围性肺癌的对比材料增强动态磁共振（MR）成像结果与肿瘤血管分布和预后的关系。材料与方法：回顾性分析94例行手术切除的小周围性肺癌患者。病理标本采用苏木精-伊红和弹性蛋白染色。免疫组织化学检测CD34和血管内皮生长因子（VEGF）。圈定的cd34阳性细胞计数为微血管。在注射大剂量加多门戊二胺之前和注射后1、2、3、4、5、6和8分钟进行动态磁共振成像。两名观察员检查了所有图像，两名病理学家进行了所有组织学分析；一项决定是协商一致作出的。最大增强比（MER）、注射完成到最大信号强度点（Tmax）的时间间隔、冲刷比、时间-信号强度曲线斜率值与微血管密度相关。比较vegf阳性和vegf阴性肿瘤。所有统计分析均采用非参数方法进行。结果：MER与斜率值呈正相关，Tmax与微血管计数呈负相关（Spearman秩检验，P< 0.0001，均比较）。弹力纤维和胶原纤维的分布与洗脱比相关（Kruskal-Wallis检验，P< 0.001）。vegf阳性肿瘤的斜率值与vegf阴性肿瘤的斜率值差异有统计学意义（Mann-Whitney U检验，P< 0.0001）。vegf阳性肿瘤患者的总生存期明显短于vegf阴性肿瘤患者（log-rank检验，P< 0.0001）。结论：动态磁共振成像结果与肿瘤血管分布相关，可能有助于预测预后。

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.