Flow volume and shunt quantification in pediatric congenital heart disease by real-time magnetic resonance velocity mapping -: A validation study
Flow volume and shunt quantification in pediatric congenital heart disease by real-time magnetic resonance velocity mapping -: A validation study
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DOI：
10.1161/01.cir.0000126494.66859.a2
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发表时间：
2004-04-27
期刊：
影响因子：
37.8
通讯作者：
Beerbaum, P
中科院分区：
文献类型：
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作者：
Körperich, H;Gieseke, J;Beerbaum, P
背景-相位对比磁共振实时血流定量(PC-MRI)可以为先天性心脏病提供独特的血流动力学信息，但现有技术有重要的局限性。方法与结果：14例心脏左向右分流、肺(Q(P))和主动脉(Q(S))的儿童患者，采用单次激发回波平面成像结合灵敏度编码的非触发自由呼吸实时PC-MRI技术，以2.7x2.7 mm的面内分辨率(视野30x34 cm(2))，每秒获得25幅相位图像。在包括2至5个呼吸周期的9.5秒周期内，每个血管获得16.6+/-2.6随后的每搏出量(范围13至22)。将结果与常规回顾性心电门控PC-MRI进行比较。常规PC-MRI的Q(P)/Q(S)平均值为1.91+/-0.64，实时PC-MRI的Q(P)/Q(S)平均值为1.94+/-0.68。经Bland-Altman分析，肺动脉和主动脉的血流速度相差2%~3%(Bland-Altman分析)，符合下限为-11%~-13%(Mean-2 SD)，上限为18%~19%(Mean+2 SD)，两种方法具有良好的一致性。Q(P)/Q(S)的平均差值为1%，符合度范围为-18%~22%(均数+/-2SD)。与常规PC-MRI相比，实时PC-MRI在体外(搏动性流动体模)中观察到高重复性，但存在一定的血流高估现象。每搏搏动体积在体内的变异为6.1+/-2.3%，在体外为3.7+/-0.3%。结论采用非触发的PC-MRI回声平面成像和灵敏度编码的非触发实时PC-MRI可以在几秒内量化肺动脉和主动脉血流，从而实现从左到右的分流。良好的空间/时间分辨率和大视野可能使该序列在先天性心脏病的多种应用中具有价值。
Background-Flow quantification in real time by phase-contrast MRI (PC-MRI) may provide unique hemodynamic information in congenital heart disease, but available techniques have important limitations. We sought to validate a novel real-time magnetic resonance flow sequence in children.Methods and Results-In 14 pediatric patients (mean age 5.2 +/- 2.0 years) with cardiac left-to-right shunt, pulmonary (Q(p)) and aortic (Q(s)) flow rates were determined by nontriggered free-breathing real-time PC-MRI with single-shot echo-planar imaging combined with sensitivity encoding, which yielded 25 phase images per second at 2.7 x 2.7-mm in-plane resolution (field of view 30x34 cm(2)). Over a 9.5-second period that included 2 to 5 respiratory cycles, 16.6+/-2.6 subsequent stroke volumes (range 13 to 22) were acquired in each vessel. Results were compared with conventional retrospectively ECG-gated PC-MRI. Mean Q(p)/Q(s) by conventional PC-MRI was 1.91+/-0.64, and it was 1.94+/-0.68 (mean+/-SD) by real-time PC-MRI. For blood flow rate through pulmonary artery and aorta, we found differences of 2% to 3% (Bland-Altman analysis), with lower limits of agreement of -11% to -13% (mean-2 SD) and upper limits of 18% to 19% (mean+2 SD), which demonstrated good agreement between both methods. Mean difference for Q(p)/Q(s) was 1%, with limits of agreement ranging between -18% and 22% (mean+/-2 SD). High repeatability but some flow overestimation was observed in vitro (pulsatile flow phantom) with real-time PC-MRI, whereas conventional PC-MRI was accurate. Beat-to-beat stroke-volume variation was 6.1+/-2.3% in vivo and 3.7+/-0.3% in vitro.Conclusions-Beat-to-beat quantification of pulmonary and aortic flows and hence left-to-right shunt within a few seconds is reliable by nontriggered real-time PC-MRI with echo-planar imaging and sensitivity encoding. Good spatial/temporal resolution and a large field of view may render the sequence valuable for multiple applications in congenital heart disease.