Wikström M G, Moseley M E, White D L, Dupon J W, Winkelhake J L, Kopplin J, Brasch R C
Department of Radiology, University of California, San Francisco 94143.
Invest Radiol. 1989 Aug;24(8):609-15. doi: 10.1097/00004424-198908000-00007.
The study aim was to define potential differences and advantages in magnetic resonance (MR) patterns of tumoral contrast enhancement using either a small molecular, extracellular fluid contrast enhancer [Gd-DTPA] or a macromolecular agent [albumin-(Gd-DTPA)20], designed for primary intravascular biodistribution. MR images of 25 mice with implanted fibrosarcomas were obtained before and repeatedly for up to 120 minutes after injection of either Gd-DTPA [0.2 mmol/kg, n = 11] or albumin-(Gd-DTPA) [0.0029 mmol/kg, n = 14]. Histologically, this hypovascular tumor contained zones of viable tissue and non-viable, necrotic tissue. Using either type of contrast media, the viable portions enhanced strongly, up to 152% and the necrotic portions enhanced poorly, less than 31%. However, the time-course of enhancement differed between contrast agents. Gd-DTPA tended to provide maximal enhancement soon after administration with no significant changes over two hours. Enhancement from albumin-(Gd-DTPA) was weak initially, corresponding to tumor hypovascularity, but over two hours the signal of the viable tumor zones progressively increased in intensity. This gradual tumoral accumulation of the macromolecular agent within the tumor was considered to reflect abnormal capillary permeability, associated with neovascularity. Thus, the increasing intensity within the neoplastic tissues over time, reflecting abnormal capillary permeability for macromolecules, may serve as a useful, albeit indirect, marker of neoplasia.
本研究的目的是确定使用小分子细胞外液对比增强剂[钆喷酸葡胺（Gd-DTPA）]或为主要血管内生物分布设计的大分子试剂[白蛋白-（Gd-DTPA）20]时，肿瘤对比增强磁共振（MR）模式中的潜在差异和优势。在注射Gd-DTPA[0.2 mmol/kg，n = 11]或白蛋白-（Gd-DTPA）[0.0029 mmol/kg，n = 14]之前及之后长达120分钟内，对25只植入纤维肉瘤的小鼠反复进行MR成像。组织学上，这种低血运肿瘤包含存活组织区域和非存活的坏死组织区域。使用任何一种造影剂时，存活部分均强烈增强，增强幅度高达152%，而坏死部分增强较差，增强幅度小于31%。然而，不同造影剂的增强时间进程有所不同。Gd-DTPA给药后很快达到最大增强，两小时内无显著变化。白蛋白-（Gd-DTPA）最初增强较弱，这与肿瘤低血运相符，但两小时内存活肿瘤区域的信号强度逐渐增加。这种大分子试剂在肿瘤内的逐渐蓄积被认为反映了与新生血管形成相关的异常毛细血管通透性。因此，随着时间推移肿瘤组织内强度增加，反映了大分子的异常毛细血管通透性，这可能是一种有用的（尽管是间接的）肿瘤标记物。
