Morgan Stanley Children's Hospital of New York Presbyterian, Columbia University Medical Center, New York, New York, USA.
J Cardiovasc Magn Reson. 2010 Mar 5;12(1):11. doi: 10.1186/1532-429X-12-11.
One potential source of error in phase contrast (PC) congenital CMR flow measurements is caused by phase offsets due to local non-compensated eddy currents. Phantom correction of these phase offset errors has been shown to result in more accurate measurements of blood flow in adults with structurally normal hearts. We report the effect of phantom correction on PC flow measurements at a clinical congenital CMR program.
Flow was measured in the ascending aorta, main pulmonary artery, and right and left pulmonary arteries as clinically indicated, and additional values such as Qp/Qs were derived from these measurements. Phantom correction in our study population of 149 patients resulted in clinically significant changes in 13% to 48% of these phase-contrast measurements in patients with known or suspected heart disease. Overall, 640 measurements or calculated values were analyzed, and clinically significant changes were found in 31%. Larger vessels were associated with greater phase offset errors, with 22% of the changes in PC flow measurements attributed to the size of the vessel measured. In patients with structurally normal hearts, the pulmonary-to-systemic flow ratio after phantom correction was closer to 1.0 than before phantom correction. There was no significant difference in the effect of phantom correction for patients with tetralogy of Fallot as compared to the group as a whole.
Phantom correction often resulted in clinically significant changes in PC blood flow measurements in patients with known or suspected congenital heart disease. In laboratories performing clinical CMR with suspected phase offset errors of significance, the routine use of phantom correction for PC flow measurements should be considered.
在相位对比（PC）先天性 CMR 流量测量中，一个潜在的误差源是由于局部未补偿的涡流引起的相位偏移。已经证明，对这些相位偏移误差进行体模校正可以更准确地测量结构正常的成年人的血流量。我们报告了在临床先天性 CMR 程序中体模校正对 PC 流量测量的影响。
在升主动脉、主肺动脉、右肺动脉和左肺动脉中按临床需要测量流量，并从这些测量中得出 Qp/Qs 等额外值。在我们的 149 例患者的研究人群中，体模校正导致已知或疑似心脏病患者中 13%至 48%的相位对比测量值发生临床显著变化。总体上，分析了 640 次测量或计算值，发现 31%的测量值有临床显著变化。较大的血管与较大的相位偏移误差相关，22%的 PC 流量测量变化归因于所测量血管的大小。在结构正常的心脏患者中，校正体模后的肺循环与体循环比值更接近 1.0，而校正体模前则更接近 1.0。校正体模对法洛四联症患者的影响与对整个组的影响没有显著差异。
在已知或疑似先天性心脏病患者中，体模校正通常会导致 PC 血流测量值发生临床显著变化。在进行临床 CMR 且怀疑存在显著相位偏移误差的实验室中，应考虑常规使用体模校正 PC 流量测量。
