Daldrup H, Shames D M, Wendland M, Okuhata Y, Link T M, Rosenau W, Lu Y, Brasch R C
Department of Radiology, University of California, San Francisco 94143-0628, USA.
AJR Am J Roentgenol. 1998 Oct;171(4):941-9. doi: 10.2214/ajr.171.4.9762973.
The endothelial integrity of microvessels is disrupted in malignant tumors. Quantitative assays of tumor microvascular characteristics based on dynamic MR imaging were correlated with histopathologic grade in mammary soft-tissue tumors.
A spectrum of tumors, benign through highly malignant, was induced in 33 female rats by administration of N-ethyl-N-nitrosourea, a potent carcinogen. Dynamic contrast-enhanced MR imaging was performed using a small-molecular contrast medium (gadopentetate, molecular weight = 0.5 kDa) and a macromolecular contrast medium (albumin-(Gd-DTPA)30, molecular weight = 92 kDa) at an interval of 1-2 days. Permeability surface area product (PS), as estimated by the corresponding endothelial transfer coefficient (K(PS)), and fractional plasma volume (fPV) were calculated for each tumor and each contrast agent using a two-compartment bidirectional kinetic model. MR imaging microvascular characteristics were correlated with histopathologic tumor grade.
Tumor permeability to macromolecular contrast medium, characterized by K(PS), showed a highly positive correlation with tumor grade (r2 = .76, p < 10(-10)). K(PS) values were zero for all benign and some low-grade carcinomas, greater than zero in all other carcinomas, and increased in magnitude with higher tumor grade. A considerably smaller but significantly positive correlation was found between fPV and tumor grade using macromolecular contrast medium (r2 = .25, p < .003). No correlation between K(PS) or fPV values and tumor grade was found using gadopentetate (r2 = .01, p > .95 and r2 = .03, p > .15, respectively).
Quantitative tumor microvascular permeability assays generated with macromolecular MR imaging contrast medium correlate closely with histologic tumor grade. No significant correlation is found using small-molecular gadopentetate.
恶性肿瘤中微血管的内皮完整性遭到破坏。基于动态磁共振成像的肿瘤微血管特征定量分析与乳腺软组织肿瘤的组织病理学分级相关。
通过给予强效致癌物N-乙基-N-亚硝基脲，在33只雌性大鼠中诱发了一系列从良性到高度恶性的肿瘤。使用小分子造影剂（钆喷酸葡胺，分子量 = 0.5 kDa）和大分子造影剂（白蛋白-(钆-二乙三胺五乙酸)30，分子量 = 92 kDa），每隔1 - 2天进行一次动态对比增强磁共振成像。使用双室双向动力学模型为每个肿瘤和每种造影剂计算通透性表面积乘积（PS），由相应的内皮转运系数（K(PS)）估算得出，以及血浆容积分数（fPV）。磁共振成像微血管特征与肿瘤组织病理学分级相关。
以K(PS)为特征的肿瘤对大分子造影剂的通透性与肿瘤分级呈高度正相关（r2 = 0.76，p < 10(-10)）。所有良性肿瘤和一些低级别癌的K(PS)值为零，所有其他癌的K(PS)值大于零，且随着肿瘤分级升高其数值增大。使用大分子造影剂时，fPV与肿瘤分级之间存在较小但显著的正相关（r2 = 0.25，p < 0.003）。使用钆喷酸葡胺时，未发现K(PS)或fPV值与肿瘤分级之间存在相关性（分别为r2 = 0.01，p > 0.95和r2 = 0.03，p > 0.15）。
使用大分子磁共振成像造影剂进行的肿瘤微血管通透性定量分析与肿瘤组织学分级密切相关。使用小分子钆喷酸葡胺未发现显著相关性。
