Vessel size index measurements in a rat model of glioma: comparison of the dynamic (Gd) and steady-state (iron-oxide) susceptibility contrast MRI approaches
Vessel size index measurements in a rat model of glioma: comparison of the dynamic (Gd) and steady-state (iron-oxide) susceptibility contrast MRI approaches
复制标题
DOI：
10.1002/nbm.1734
复制
发表时间：
2012-02-01
影响因子：
2.9
通讯作者：
Barbier, Emmanuel L.
中科院分区：
文献类型：
--
作者：
Pannetier, Nicolas;Lemasson, Benjamin;Barbier, Emmanuel L.
血管尺寸指数（VSI）是一个与血管直径分布相关的参数，可以使用两种MRI方法进行估计：（i）注射Gd-螯合物推注后的动态磁化率对比（DSC）MRI。该技术通常应用于临床，以评估患者的颅内组织灌注;（ii）与USPIO造影剂的稳态敏感度对比，在此将其视为标准方法。这些药物还不能用于人类，稳态方法目前仅限于动物研究。目的是比较这两种方法对C6胶质瘤大鼠（n = 7）获得的VSI估计值。在第一阶段中，通过连续两次注射Gd-螯合物（Gd-1和Gd-2）估计VSI。在第二次治疗中（4小时后），使用USPIO估计VSI。我们的研究结果表明，这两种方法在对侧（VSI{USPIO} = 7.5 +/- 2.0 μ m，VSI{Gd-1} = 6.5 +/- 0.7 μ m）和脑肿瘤组织（VSI{USPIO} = 19.4 +/- 7.1 μ m，VSI{Gd-1} = 16.6 +/- 4.5 μ m）中产生了相当的VSI估计值。我们还观察到，在存在BBB渗漏的情况下（因为它通常发生在脑肿瘤中），应用Gd-螯合物的预载改善了DSC方法在对侧（VSI{Gd-2} = 7.1 +/- 0.4 μ m）和脑肿瘤组织（VSI{Gd-2} = 18.5 +/- 4.3 μ m）中的VSI估计，但不是强制性的。VSI估计值似乎对Gd外渗相关的T-1变化不敏感。这些结果表明，在3 T或更高磁场下，采用DSC方法可以在患者中获得稳健的VSI估计值。版权所有（C）2011约翰威利父子有限公司
Vessel size index (VSI), a parameter related to the distribution of vessel diameters, may be estimated using two MRI approaches: (i) dynamic susceptibility contrast (DSC) MRI following the injection of a bolus of Gd-chelate. This technique is routinely applied in the clinic to assess intracranial tissue perfusion in patients; (ii) steady-state susceptibility contrast with USPIO contrast agents, which is considered here as the standard method. Such agents are not available for human yet and the steady-state approach is currently limited to animal studies. The aim is to compare VSI estimates obtained with these two approaches on rats bearing C6 glioma (n = 7). In a first session, VSI was estimated from two consecutive injections of Gd-Chelate (Gd-1 and Gd-2). In a second session (4 hours later), VSI was estimated using USPIO. Our findings indicate that both approaches yield comparable VSI estimates both in contralateral (VSI{USPIO} = 7.5 +/- 2.0 mu m, VSI{Gd-1} = 6.5 +/- 0.7 mu m) and in brain tumour tissues (VSI{USPIO} = 19.4 +/- 7.1 mu m, VSI{Gd-1} = 16.6 +/- 4.5 mu m). We also observed that, in the presence of BBB leakage (as it occurs typically in brain tumours), applying a preload of Gd-chelate improves the VSI estimate with the DSC approach both in contralateral (VSI{Gd-2} = 7.1 +/- 0.4 mu m) and in brain tumour tissues (VSI{Gd-2} = 18.5 +/- 4.3 mu m) but is not mandatory. VSI estimates do not appear to be sensitive to T-1 changes related to Gd extravasation. These results suggest that robust VSI estimates may be obtained in patients at 3 T or higher magnetic fields with the DSC approach. Copyright (C) 2011 John Wiley & Sons, Ltd.