INVERSION-RECOVERY EPI OF BOLUS TRANSIT IN RAT MYOCARDIUM USING INTRAVASCULAR AND EXTRAVASCULAR GADOLINIUM-BASED MR CONTRAST-MEDIA - DOSE EFFECTS ON PEAK SIGNAL ENHANCEMENT
INVERSION-RECOVERY EPI OF BOLUS TRANSIT IN RAT MYOCARDIUM USING INTRAVASCULAR AND EXTRAVASCULAR GADOLINIUM-BASED MR CONTRAST-MEDIA - DOSE EFFECTS ON PEAK SIGNAL ENHANCEMENT
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DOI：
10.1002/mrm.1910320307
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发表时间：
1994-09-01
影响因子：
3.3
通讯作者：
HIGGINS, CB
中科院分区：
文献类型：
--
作者：
WENDLAND, MF;SAEED, M;HIGGINS, CB
反转恢复梯度回波平面成像（TI/TR/TE = 700/2000/10 ms）用于动态监测血管内（GdDOTA聚赖氨酸）和血管外（GdDTPA-BMA）造影剂通过正常大鼠心肌的首次通过。结果发现，心肌增强随着血管内药剂剂量的增加而增加至接近完全放松强度的50%的极限值，这与第一次通过时心肌含水量增加40%一致。更大剂量不会进一步增加峰值反应。另一方面，血管外药物在整个剂量范围内引起逐渐增加的增强，最终值为完全松弛强度的68 +/- 2%。两种药物的剂量依赖性曲线与单指数T-1松弛不一致。结论是：（a）心肌水的区室化与限制的心肌水扩散相结合，限制了丸剂输送过程中的峰值响应;（B）输送过程中血管外药剂的提取使峰值响应高于从限制在血管体积中的药剂获得的峰值响应;以及（c）假设简单单指数T-1弛豫以推导时间-密度曲线不能充分描述信号强度变化R（1）和对比剂浓度之间的关系。
Inversion recovery gradient recalled echo planar imaging (TI/TR/TE = 700/2000/10 ms) was used to dynamically monitor the first pass of an intravascular (GdDOTA polylysine) and an extravascular (GdDTPA-BMA) contrast agent through normal rat myocardium. It was found that myocardial enhancement increased with dose of the intravascular agent to a limiting value of similar to 50% of fully relaxed intensity, consistent with enhancement of 40% of myocardial water content during the first pass. Larger doses produced no further increase in peak response. On the other hand, the extravascular agent caused incrementally increased enhancement throughout the dose range examined to a final value of 68 +/- 2% of fully relaxed intensity. The profile of dose dependence for both agents was inconsistent with monoexponential T-1 relaxation. It was concluded that: (a) compartmentalization of myocardial water combined with restricted myocardial water diffusion limits the peak response during bolus transit; (b) extraction of the extravascular agent during transit elevates the peak response over that obtained from agent confined to the vascular volume; and (c) models that assume simple monoexponential T-1 relaxation to derive time-density curves do not adequately describe the relationship between changes in signal intensity, R(1) and contrast concentration.