Measurements of extracellular volume fraction and capillary permeability in tissues using dynamic spin-lattice relaxometry: studies in rabbit muscles
Measurements of extracellular volume fraction and capillary permeability in tissues using dynamic spin-lattice relaxometry: studies in rabbit muscles
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DOI：
10.1016/s0730-725x(02)00638-0
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发表时间：
2003-02-01
影响因子：
2.5
通讯作者：
Joffre, F
中科院分区：
文献类型：
--
作者：
Vincensini, D;Dedieu, V;Joffre, F
施用钆造影剂 (Gd-DTPA) 后的动态 MR 纵向 R-1 松弛测量已用于体内测量兔肌肉的细胞外体积分数 (v) 和毛细血管通透性 (k min(-1))，以区分红色慢肌纤维和白色快肌纤维类型。为此，使用了协议成像序列，该序列允许在造影剂摄取期间快速进行 R-1 测量。生理组织参数 k 和 v 是通过假设简化的单指数等离子体模型的计算程序获得的。结果显示，慢肌半膜固有肌 (SP) 中的纤维大小约为其两倍，其中含有 100% 氧化型 I 纤维。在快肌股直肌 (RF) 中，仅含有 6% 的 I 型纤维类型。已发现 (SP) 的毛细血管渗透性为 0.25 +/- 0.02 min(-1)，(RF) 的毛细血管渗透性为 0.10 +/- 0.01 min(-1)。同样，细胞外体积分数分别为 0.189 +/- 0.015 和 0.082 +/- 0.006，与文献数据和侵入性放射性核素测量获得的实验结果非常一致。对于 10 只研究动物，不同肌纤维类型的细胞外体积分数和毛细血管渗透性没有观察到动物之间的显着差异。所使用的动态松弛测量方法易于在传统 MR 成像仪上实施，并且在肌肉疾病中具有潜在应用。该方法还具有基于细胞外体积和毛细血管通透性定量的组织表征的潜在应用。特别是，该方法可用于评估肿瘤及其对治疗的反应。 (C) 2003 Elsevier Science Inc. 保留所有权利。
Dynamic MR longitudinal R-1 relaxometry after administration of a gadolinium contrast bolus (Gd-DTPA) has been used for in vivo measurements of the extracellular volume fraction (v) and the capillary permeability (k min(-1)) in rabbit muscles to distinguish between red slow- and white fast-twitch muscle fiber types. For this purpose a protocol imaging sequence has been used which allows fast R-1 measurements during the contrast agent uptake. Physiological tissue parameters, k and v, were obtained by computing procedures assuming a simplified monoexponential plasma model. These were shown to be about twice as large in the slow-twitch semimembranosous proprius muscle (SP), containing 100% oxidative type-I fiber, that. in the fast-twitch rectus femorus muscle (RF), containing only 6% type-I fiber type.The capillary permeability has been found to be 0.25 +/- 0.02 min(-1) for the (SP) and 0.10 +/- 0.01 min(-1) for the (RF). Similarly, the extracellular volume fractions were 0.189 +/- 0.015 and 0.082 +/- 0.006 respectively, in close agreement with literature data and experimental results obtained by invasive radionuclide measurements. For the pool of the 10 studied animals, no significant variation among animals was observed in the extracellular volume fraction and the capillary permeability for the different muscle fiber types.The dynamic relaxometry method used is easy to implement on conventional MR imagers and has potential applications in muscle diseases. The method has also potential applications for tissue characterization based on extracellular volume and capillary permeability quantification. In particular, the method can be used for the evaluation of tumors and their responses to therapies. (C) 2003 Elsevier Science Inc. All rights reserved.