Assessment of Diffuse Myocardial Fibrosis in Rats Using Small-Animal Look-Locker Inversion Recovery T1 Mapping
Assessment of Diffuse Myocardial Fibrosis in Rats Using Small-Animal Look-Locker Inversion Recovery T1 Mapping
复制标题
DOI：
10.1161/circimaging.111.966796
复制
发表时间：
2011-11-01
影响因子：
7.5
通讯作者：
Kuehne, Titus
中科院分区：
文献类型：
--
作者：
Messroghli, Daniel R.;Nordmeyer, Sarah;Kuehne, Titus
心肌和血液中钆喷酸葡胺的浓度可以通过T1测量来评估，并可用于计算心肌的细胞外容积（ECV）。我们假设，弥漫性心肌纤维化的小动物模型，可以通过测量心肌ECV使用小动物Look-Rolling反转恢复T1 mapping.Methods和Results-Sprague-道利大鼠（n = 10）进行定量评估连续血管紧张素-2（AT 2）输注2周，通过皮下植入minipump系统。在AT 2输注前后进行磁共振成像（MRI）。MRI方案包括多层电影成像和对比前后的小动物Look-Perth反转恢复T1标测和晚期钆增强成像。根据红细胞压积、血液和心肌的T1值计算心肌ECV。在AT 2输注过程中，平均+/- SD收缩压从122 +/- 10.9升高至152 +/- 27.5 mm Hg（P=0.003）。AT 2给药组动物的标准化心脏重量显著高于对照同窝动物（P=0.033）。电影MRI记录了向心性左心室肥大。治疗后对比心肌T1时间缩短（中位数[四分位距]，712 [63] vs 820 [131] ms; P=0.002）。心肌ECV从治疗前的17.2%（4.3%）增加到治疗后的23.0%（6.2%）（P=0.031），并伴有心肌组织学上的血管周围纤维化和微瘢痕形成。有一个中等水平的相关性之间的ECV和胶原体积分数，通过组织学分析评估（r=0.69，P=0.013）。结论在小动物模型的左心室肥厚，对比增强T1映射可以用来检测弥漫性心肌纤维化心肌ECV的量化。(Circ血管造影。2011;4：636-640）。
Background-The concentration of gadopentetate dimeglumine in myocardium and blood can be assessed from T1 measurements and can be used to calculate the extracellular volume (ECV) of the myocardium. We hypothesized that diffuse myocardial fibrosis in a small-animal model could be quantitatively assessed by measuring myocardial ECV using small-animal Look-Locker inversion recovery T1 mapping.Methods and Results-Sprague-Dawley rats (n = 10) were subjected to continuous angiotensin-2 (AT2) infusion for 2 weeks via a subcutaneously implanted minipump system. Magnetic resonance imaging (MRI) was performed both before and after AT2 infusion. The MRI protocol included multislice cine imaging and before-and-after contrast small-animal Look-Locker inversion recovery T1 mapping and late gadolinium enhancement imaging. Myocardial ECV was calculated from hematocrit and T1 values of blood and myocardium. During the course of AT2 infusion, the mean +/- SD systolic blood pressure increased from 122 +/- 10.9 to 152 +/- 27.5 mm Hg (P=0.003). Normalized heart weight was significantly higher in AT2-treated animals than in control littermates (P=0.033). Cine MRI documented concentric left ventricular hypertrophy. Postcontrast myocardial T1 times were shortened after treatment (median [interquartile range], 712 [63] versus 820 [131] ms; P=0.002). Myocardial ECV increased from 17.2% (4.3%) before to 23.0% (6.2%) after AT2 treatment (P=0.031), which was accompanied by perivascular fibrosis and microscarring on myocardial histological analysis. There was a moderate level of correlation between ECV and collagen volume fraction, as assessed by histological analysis (r=0.69, P=0.013).Conclusions-In a small-animal model of left ventricular hypertrophy, contrast-enhanced T1 mapping can be used to detect diffuse myocardial fibrosis by quantification of myocardial ECV. (Circ Cardiovasc Imaging. 2011;4:636-640.)