Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45122, Essen, Germany.
Eur Radiol. 2012 Dec;22(12):2679-87. doi: 10.1007/s00330-012-2547-6. Epub 2012 Jul 10.
To assess the diagnostic accuracy of phonocardiogram (PCG) gated velocity-encoded phase contrast magnetic resonance imaging (MRI).
Flow quantification above the aortic valve was performed in 68 patients by acquiring a retrospectively PCG- and a retrospectively ECG-gated velocity-encoded GE-sequence at 1.5 T. Peak velocity (PV), average velocity (AV), forward volume (FV), reverse volume (RV), net forward volume (NFV), as well as the regurgitant fraction (RF) were assessed for both datasets, as well as for the PCG-gated datasets after compensation for the PCG trigger delay.
PCG-gated image acquisition was feasible in 64 patients, ECG-gated in all patients. PCG-gated flow quantification overestimated PV (Δ 3.8 ± 14.1 cm/s; P = 0.037) and underestimated FV (Δ -4.9 ± 15.7 ml; P = 0.015) and NFV (Δ -4.5 ± 16.5 ml; P = 0.033) compared with ECG-gated imaging. After compensation for the PCG trigger delay, differences were only observed for PV (Δ 3.8 ± 14.1 cm/s; P = 0.037). Wide limits of agreement between PCG- and ECG-gated flow quantification were observed for all variables (PV: -23.9 to 31.4 cm/s; AV: -4.5 to 3.9 cm/s; FV: -35.6 to 25.9 ml; RV: -8.0 to 7.2 ml; NFV: -36.8 to 27.8 ml; RF: -10.4 to 10.2 %).
The present study demonstrates that PCG gating in its current form is not reliable enough for flow quantification based on velocity-encoded phase contrast gradient echo (GE) sequences.
Phonocardiogram gating is an alternative to ECG-gating in cardiac MRI. Phonocardiogram gating shows only limited reliability for velocity-encoded cardiac MRI. Further refinements of the post-processing algorithm are necessary.
评估心音图（PCG）门控速度编码相位对比磁共振成像（MRI）的诊断准确性。
在 68 例患者中通过获取回顾性 PCG 门控和回顾性 ECG 门控速度编码 GE 序列在 1.5T 上进行主动脉瓣上方的流量定量。评估两个数据集的峰值速度（PV）、平均速度（AV）、前向容积（FV）、反向容积（RV）、净前向容积（NFV）以及反流分数（RF），以及 PCG 门控数据集在补偿 PCG 触发延迟后的结果。
64 例患者可行 PCG 门控图像采集，所有患者可行 ECG 门控图像采集。与 ECG 门控成像相比，PCG 门控流量定量高估了 PV（Δ3.8±14.1cm/s；P=0.037），低估了 FV（Δ-4.9±15.7ml；P=0.015）和 NFV（Δ-4.5±16.5ml；P=0.033）。补偿 PCG 触发延迟后，仅观察到 PV 存在差异（Δ3.8±14.1cm/s；P=0.037）。所有变量的 PCG 和 ECG 门控流量定量之间存在广泛的一致性限制（PV：-23.9 至 31.4cm/s；AV：-4.5 至 3.9cm/s；FV：-35.6 至 25.9ml；RV：-8.0 至 7.2ml；NFV：-36.8 至 27.8ml；RF：-10.4 至 10.2%）。
本研究表明，PCG 门控目前的形式对于基于速度编码相位对比梯度回波（GE）序列的流量定量来说还不够可靠。
心音图门控是心脏 MRI 中 ECG 门控的替代方法。心音图门控对于速度编码心脏 MRI 的可靠性有限。需要进一步改进后处理算法。
