Myocardial extravascular extracellular volume fraction measurement by gadolinium cardiovascular magnetic resonance in humans: slow infusion versus bolus.
Myocardial extravascular extracellular volume fraction measurement by gadolinium cardiovascular magnetic resonance in humans: slow infusion versus bolus.
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DOI：
10.1186/1532-429x-13-16
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发表时间：
2011-03-04
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影响因子：
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通讯作者：
Wong TC
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作者：
Schelbert EB;Testa SM;Meier CG;Ceyrolles WJ;Levenson JE;Blair AJ;Kellman P;Jones BL;Ludwig DR;Schwartzman D;Shroff SG;Wong TC
心肌血管外细胞外容积分数（Ve）测量量化了常规晚期钆（Gd）增强（LGE）不易检测到的弥漫性纤维化。Ve测量需要等离子体和间隙Gd对比度之间的稳态平衡。虽然恒定输注产生稳态，但尚不清楚简单的推注是否也能达到稳态。鉴于Gd的清除相对较慢，我们假设推注技术可准确测量Ve，从而有助于将心肌纤维化定量整合到心血管磁共振（CMR）工作流程中。假设技术之间的等效性，我们进一步假设Ve测量在扫描中是可重现的。在10名志愿者（年龄20-81岁，中位数33岁，3名女性）中，我们比较了来自两次扫描的单个短轴切片的连续Ve测量值：第一次，在恒定输注期间，第二次，在另一天推注（0.2 mmol/kg钆特醇）后12-50 min。当连续血液和心肌T1数据变化<5%时，定义为输注期间的稳态。我们在1.5 T Siemens扫描仪上使用单次激发的改良Look T1反转恢复序列（MOLLI）和平衡SSFP测量T1。为了缩短屏气时间，采用较短的采样方案测量T1值，并在CuSO 4-琼脂体模中采用自旋回波弛豫法（TR = 15秒）进行验证。将10例受试者的连续输注与推注Ve测量值（n = 205）与具有可交换相关矩阵的广义估计方程（GEE）进行比较。LGE图像也在推注后12-30分钟获得。没有受试者在测量Ve的短轴切片附近显示LGE。通过恒定输注和推注，Ve范围分别为19.3-29.2%和18.4-29.1%。在GEE模型中，通过恒定输注和推注进行的系列Ve测量没有显著差异（差异= 0.1%，p = 0.38）。对于这两种技术，即使在调整心率后，GEE模型中的Ve与年龄密切相关（两者均为p < 0.01）。这两种技术相同的排序老年人具有较高的平均Ve值。简单推注后12-50分钟即可可靠、准确地测量心肌Ve。Ve测量在CMR扫描中也是可重复的。Ve估计可以很容易地集成到CMR工作流程中，这可以简化涉及心肌纤维化定量的研究应用。
Myocardial extravascular extracellular volume fraction (Ve) measures quantify diffuse fibrosis not readily detectable by conventional late gadolinium (Gd) enhancement (LGE). Ve measurement requires steady state equilibrium between plasma and interstitial Gd contrast. While a constant infusion produces steady state, it is unclear whether a simple bolus can do the same. Given the relatively slow clearance of Gd, we hypothesized that a bolus technique accurately measures Ve, thus facilitating integration of myocardial fibrosis quantification into cardiovascular magnetic resonance (CMR) workflow routines. Assuming equivalence between techniques, we further hypothesized that Ve measures would be reproducible across scans. In 10 volunteers (ages 20-81, median 33 yr, 3 females), we compared serial Ve measures from a single short axis slice from two scans: first, during a constant infusion, and second, 12-50 min after a bolus (0.2 mmol/kg gadoteridol) on another day. Steady state during infusion was defined when serial blood and myocardial T1 data varied <5%. We measured T1 on a 1.5 T Siemens scanner using a single-shot modified Look Locker inversion recovery sequence (MOLLI) with balanced SSFP. To shorten breath hold times, T1 values were measured with a shorter sampling scheme that was validated with spin echo relaxometry (TR = 15 sec) in CuSO4-Agar phantoms. Serial infusion vs. bolus Ve measures (n = 205) from the 10 subjects were compared with generalized estimating equations (GEE) with exchangeable correlation matrices. LGE images were also acquired 12-30 minutes after the bolus. No subject exhibited LGE near the short axis slices where Ve was measured. The Ve range was 19.3-29.2% and 18.4-29.1% by constant infusion and bolus, respectively. In GEE models, serial Ve measures by constant infusion and bolus did not differ significantly (difference = 0.1%, p = 0.38). For both techniques, Ve was strongly related to age (p < 0.01 for both) in GEE models, even after adjusting for heart rate. Both techniques identically sorted older individuals with higher mean Ve values. Myocardial Ve can be measured reliably and accurately 12-50 minutes after a simple bolus. Ve measures are also reproducible across CMR scans. Ve estimation can be integrated into CMR workflow easily, which may simplify research applications involving the quantification of myocardial fibrosis.