Validation of magnetic resonance phase-contrast flow measurements in the main pulmonary artery and aorta using perivascular ultrasound in a large animal model
Validation of magnetic resonance phase-contrast flow measurements in the main pulmonary artery and aorta using perivascular ultrasound in a large animal model
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DOI：
10.1097/rli.0b013e318169015d
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发表时间：
2008-06-01
影响因子：
6.7
通讯作者：
Szabo, Gabor
中科院分区：
文献类型：
--
作者：
Ley, Sebastian;Unterhinninghofen, Roland;Szabo, Gabor
目的：相位对比流动磁共振成像(PC-MRI)测量是一种公认的无创性血流动力学评估技术。然而，缺乏关于PC-Flow准确性的活体验证数据，特别是在非生理性血流动力学条件下。本研究的目的是：1)在不同的血流动力学条件下，利用血管周围超声验证主肺动脉和升主动脉的PC-Flow；2)探讨PC-MRI与有创压力测量的关系。材料和方法：健康开胸猪5只。超声测量在MRI单元外使用可拆卸的MR台进行。在超声流量测量的同时，还进行了有创压力测量。使用Flash二维序列进行PC-MRI(1.5T MRI)测量。结果：正常血压下的血流量超声为2.7±0.6 L/min，PC-MRI为2.8±0.6 L/min(P=0.17)。高张时血流量分别增加至3.1±-0.7和2.7±0.8 L/min(P=0.0 1)。降压时血流量分别降至1·7±-0·5和1·7+/-0·5 L/分(P=0·7)。超声和PC-MRI测量结果之间有很好的线性相关性(r=0.89)。个体内部一致性的95%限度对应于-36%至44%的相对差异。血压正常组为91 mm Hg，高渗组为111 mm Hg，低张组为mm Hg，MPa组为23 mm Hg，29 mm Hg，20 mm Hg。收缩压与PC-MRI平均每分钟流量和峰值流速呈良好的线性相关(AO：r=0.79，Mpa：r=0.66)。结论：MRI PC-Flow测量是一种可靠的无创性血流评价工具。磁共振成像得到的血流动力学参数与体循环和肺动脉循环中的压力具有良好的线性相关性。
Objectives: Phase-contrast flow magnetic resonance imaging (pc-MRI) measurements are an established technique for noninvasive assessment of hemodynamics. However, in vivo validation data on the accuracy of pc-flow especially for nonphysiologic hemodynamic conditions are missing. The goal of our work was 1) to validate pc-flow with perivascular ultrasound in different hemodynamic conditions in the main pulmonary artery (MPA) and ascending aorta (AO) and 2) to investigate the relation between pc-MRI and invasive pressure measurements.Materials and Methods: Five healthy pigs with opened chest were investigated. Ultrasound measurements were performed outside the MRI unit using a detachable MR-table. Parallel to ultrasound flow measurements, invasive pressure measurements were performed. PC-MRI (1.5 T MRI) measurements were done using a FLASH 2-dimensional sequence. First the animals were examined in normotonia, followed by hypertension (infusion of Arterenol) and hypotension (infusion of Sodiumnitropussid).Results: Flow measurements acquired in normotonia were 2.7 +/- 0.6 L/min (ultrasound) and 2.8 +/- 0.6 L/min for pc-MRI (not significantly different, P = 0.17). During hypertonia, the blood flow increased to 3.1 +/- 0.7 and 2.7 +/- 0.8 L/min, respectively (P = 0.01). During hypotension, the blood flow decreased to 1.7 +/- 0.5 and 1.7 +/- 0.5 L/min, respectively (P = 0.7). Am excellent linear correlation (taking all measurements together) between the ultrasound and pc-MRI measurements was found (r = 0.89). 95% Limits of intra-individual agreement correspond to relative differences of -36 to 44%. Systolic pressure measurements in the AO were 91 mm Hg (normotonic), 111 mm Hg (hypertonic), and 64 mm Hg (hypotonic) and in the MPA 23 mm Hg (normotonic), 29 mm Hg (hypertonic), and 20 mm Hg (hypotonic). Systolic pressure measurements showed good linear correlation with pc-MRI average flow per minute and peak velocity (AO: r = 0.79, MPA: r = 0.66).Conclusion: MRI pc-flow measurements are a reliable tool for noninvasive assessment of blood flow. Hemodynamic parameters derived by MRI demonstrate good linear correlations with the pressure in the systemic and pulmonary arterial circulation.