Sirlin Claude B, Vera David R, Corbeil Jacqueline A, Caballero Marlon B, Buxton Richard B, Mattrey Robert F
Department of Radiology, University of California, San Diego, 200 West Arbor Drive, San Diego, CA, USA.
Acad Radiol. 2004 Dec;11(12):1361-9. doi: 10.1016/j.acra.2004.11.016.
Magnetic resonance (MR) imaging blood pool agents offer numerous advantages for vascular and tumor imaging. The purpose of this study was to test gadolinium-diethylenetriaminepentaacetate-dextran ([Gd]DTPA-dextran) as a new water soluble macromolecular blood pool agent for MR imaging.
[Gd]DTPA-dextran (187 gadolinium atoms per dextran, molecular weight 165 kD, diameter 17.6 nm) was synthesized. Fifteen anesthetized New Zealand White rabbits with thigh VX2 tumors were scanned in a knee coil at 1.5T. Coronal 3D MR angiographic sequences were obtained before and at several time points up to 72 hours after the intravenous bolus injection of [Gd]DTPA-dextran providing gadolinium at either 0.05 (n = 4) or 0.1 mmol/kg (n = 8) or [Gd]DTPA-bismethylamide (BMA) providing gadolinium at 0.1 mmol/kg (n = 3). Time enhancement curves for aorta, cava, and tumor rim were compared by univariate General Linear Model.
Contrast enhancement of cava and aorta relative to a water phantom were significantly greater at all time points after either dose of [Gd]DTPA-dextran than after [Gd]DTPA-BMA (P < 0.01). Tumor rim enhancement was less intense for either dose of [Gd]DTPA-dextran at peak than for [Gd]DTPA-BMA (P < 0.05). Tumor rim enhancement with both doses of [Gd]DTPA-dextran became equivalent to that of [Gd]DTPA-BMA at one hour and was greater at 24 hours (P < 0.05).
[Gd]DTPA-dextran is a new macromolecular MR contrast agent that can be synthesized to carry a high density of gadolinium atoms without intra-molecular cross-linking. It provides significantly greater vascular residence time than a conventional gadolinium chelate and shows promise for MR blood pool imaging.
磁共振（MR）成像血池造影剂在血管和肿瘤成像方面具有诸多优势。本研究的目的是测试钆 - 二乙烯三胺五乙酸 - 葡聚糖（[Gd]DTPA - 葡聚糖）作为一种新型水溶性大分子MR成像血池造影剂。
合成了[Gd]DTPA - 葡聚糖（每个葡聚糖含187个钆原子，分子量165kD，直径17.6nm）。15只麻醉状态下患有大腿VX2肿瘤的新西兰白兔在1.5T场强下用膝关节线圈进行扫描。在静脉推注[Gd]DTPA - 葡聚糖（钆剂量为0.05mmol/kg，n = 4；或0.1mmol/kg，n = 8）或[Gd]DTPA - 双甲酰胺（BMA，钆剂量为0.1mmol/kg，n = 3）之前及之后的多个时间点（最长至72小时）获取冠状面3D MR血管造影序列。通过单变量通用线性模型比较主动脉、腔静脉和肿瘤边缘的时间增强曲线。
两种剂量的[Gd]DTPA - 葡聚糖给药后，腔静脉和主动脉相对于水模体的对比增强在所有时间点均显著高于[Gd]DTPA - BMA给药后（P < 0.01）。两种剂量的[Gd]DTPA - 葡聚糖在峰值时肿瘤边缘增强强度均低于[Gd]DTPA - BMA（P < 0.05）。两种剂量的[Gd]DTPA - 葡聚糖在1小时时肿瘤边缘增强与[Gd]DTPA - BMA相当，在24小时时增强程度更高（P < 0.05）。
[Gd]DTPA - 葡聚糖是一种新型大分子MR造影剂，可合成携带高密度钆原子且无需分子内交联。它提供的血管滞留时间明显长于传统钆螯合物，在MR血池成像方面显示出前景。
