Sensitivity of USPIO-enhanced R2 imaging to dynamic blood volume changes in the rat kidney.
Sensitivity of USPIO-enhanced R2 imaging to dynamic blood volume changes in the rat kidney.
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USPIO 增强 R2 成像对大鼠肾脏动态血容量变化的敏感性。
DOI：
10.1002/jmri.22526
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Prasad,PottumarthiV
中科院分区：
文献类型：
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作者：
Storey,Pippa;Ji,Lin;Li,Lu-Ping;Prasad,PottumarthiV
目的确定 MRI 与血管内造影剂联合使用是否对大鼠肾脏中药物诱导的血管舒张和血管收缩敏感。材料和方法在 25 只 Sprague Dawley 大鼠中在 3 特斯拉、存在费鲁莫托（一种具有长血浆半衰期的超小超顺磁性氧化铁 (USPIO) 剂）的情况下进行 R2 成像。通过静脉注射腺苷（一种短效血管扩张剂）或 NG-硝基-L-精氨酸甲酯（L-NAME）（一种具有已知血管收缩作用的长效一氧化氮合酶抑制剂）来控制血容量后，测量 R2 变化。作为对照，在没有费鲁莫托的情况下也检查了 R2 对腺苷和 L-NAME 的反应。结果在存在费鲁莫托的情况下，腺苷诱导 R2 显着增加，而 L-NAME 产生减少，尽管后者没有统计学意义。对照实验显示，在没有阿莫西托的情况下，R2 发生了微小的变化。一个偶然的发现是，肾脏的横截面积也随着腺苷和 L-NAME 的变化而动态变化。结论我们的结果表明，ferumoxytol 增强的 R2 成像对腺苷诱导的血管舒张很敏感。然而，对 L-NAME 的反应没有统计学意义。在没有费鲁莫托的情况下，肾脏大小的变化和 R2 的变化可能反映了肾小管体积的变化。 J.马格。共振。成像 2011；33：1091–1099。 © 2011 Wiley-Liss, Inc.
PurposeTo determine whether MRI in combination with an intravascular contrast agent is sensitive to pharmacologically induced vasodilation and vasoconstriction in the rat kidney.Materials and MethodsR2imaging was performed in 25 Sprague Dawley rats at 3 Tesla in the presence of ferumoxytol, an ultrasmall superparamagnetic iron oxide (USPIO) agent with a long plasma half‐life. R2changes were measured following manipulation of blood volume by intravenous administration of adenosine, a short‐acting vasodilator, or NG‐nitro‐L‐arginine methyl ester (L‐NAME), a long‐acting nitric oxide synthase inhibitor with known vasoconstrictive effects. As a control, R2responses to adenosine and L‐NAME were also examined in the absence of ferumoxytol.ResultsIn the presence of ferumoxytol, adenosine induced a significant increase in R2, while L‐NAME produced a reduction, although the latter was not statistically significant. Control experiments revealed small R2changes in the absence of ferumoxytol. An incidental finding was that the cross‐sectional area of the kidney also varied dynamically with adenosine and L‐NAME.ConclusionOur results suggest that ferumoxytol‐enhanced R2imaging is sensitive to adenosine‐induced vasodilation. The responses to L‐NAME, however, were not statistically significant. The variations in kidney size and the R2changes in the absence of ferumoxytol may reflect alterations in the volume of the renal tubules. J. Magn. Reson. Imaging 2011;33:1091–1099. © 2011 Wiley‐Liss, Inc.