BACKGROUND The need for background error correction in phase-contrast flow analysis has historically posed a challenge in cardiac magnetic resonance (MR) imaging. While previous studies have shown that phantom correction improves flow measurements, it impedes scanner workflow. OBJECTIVE To evaluate the efficacy of self-calibrated non-linear phase-contrast correction on flows in pediatric and congenital cardiac MR compared to phantom correction as the standard. MATERIALS AND METHODS We retrospectively identified children who had great-vessel phase-contrast and static phantom sequences acquired between January 2015 and June 2015. We applied a novel correction method to each phase-contrast sequence post hoc. Uncorrected, non-linear, and phantom-corrected flows were compared using intraclass correlation. We used paired t-tests to compare how closely non-linear and uncorrected flows approximated phantom-corrected flows. In children without intra- or extracardiac shunts or significant semilunar valvular regurgitation, we used paired t-tests to compare how closely the uncorrected pulmonary-to-systemic flow ratio (Qp:Qs) and non-linear Qp:Qs approximated phantom-corrected Qp:Qs. RESULTS We included 211 diagnostic-quality phase-contrast sequences (93 aorta, 74 main pulmonary artery [MPA], 21 left pulmonary artery [LPA], 23 right pulmonary artery [RPA]) from 108 children (median age 15 years, interquartile range 11-18 years). Intraclass correlation showed strong agreement between non-linear and phantom-corrected flow measurements but also between uncorrected and phantom-corrected flow measurements. Non-linear flow measurements did not more closely approximate phantom-corrected measurements than did uncorrected measurements for any vessel. In 39 children without significant shunting or regurgitation, mean non-linear Qp:Qs (1.07; 95% confidence interval [CI] = 1.01, 1.13) was no closer than mean uncorrected Qp:Qs (1.06; 95% CI = 1.00, 1.13) to mean phantom-corrected Qp:Qs (1.02; 95% CI = 0.98, 1.06). CONCLUSION Despite strong agreement between self-calibrated non-linear and phantom correction, cardiac flows and shunt calculations with non-linear correction were no closer to phantom-corrected measurements than those without background correction. However, phantom-corrected flows also demonstrated minimal differences from uncorrected flows. These findings suggest that in the current era, more accurate phase-contrast flow measurements might limit the need for background correction. Further investigation of the clinical impact and optimal methods of background correction in the pediatric and congenital cardiac population is needed.

中文翻译：

---

儿科和先天性心血管磁共振成像中自校准非线性相位对比校正的评估。

背景技术历来，在相衬流分析中对背景误差校正的需求在心脏磁共振（MR）成像中提出了挑战。先前的研究表明，幻像校正可以改善流量测量，但会阻碍扫描仪的工作流程。目的评估与模体校正相比，自校正非线性相位对比校正对小儿和先天性心脏MR血流的疗效。材料和方法我们回顾性鉴定了2015年1月至2015年6月之间具有大血管相衬和静态幻像序列的儿童。我们对事后的每个相衬序列应用了一种新颖的校正方法。使用类内相关性比较未校正的，非线性的和幻像校正的流。我们使用成对的t检验比较非线性和未经校正的流近似于幻像校正的流。在没有心内或心外分流或明显的半月瓣关闭不全的儿童中，我们使用配对的t检验比较未校正的肺对系统流量比（Qp：Qs）和非线性Qp：Qs近似幻像校正的Qp ：问 结果我们纳入了108名儿童（中位年龄15岁，四分位间距）的211条诊断质量相衬序列（93条主动脉，74条主肺动脉[MPA]，21条左肺动脉[LPA]，23条右肺动脉[RPA]） 11-18岁）。类内相关性显示了非线性和幻像校正的流量测量之间的强烈一致性，而且未校正和幻像校正的流量测量之间也有很强的一致性。对于任何容器，非线性流量测量都没有比未经校正的测量更接近幻像校正的测量。在39名无明显分流或反流的儿童中，平均非线性Qp：Qs（1.07; 95％置信区间[CI] = 1.01，1.13）与未校正的平均Qp：Qs（1.06; 95％CI = 1.00，1.13）并不接近。 ）表示体模校正的Qp：Qs（1.02; 95％CI = 0.98，1.06）。结论尽管自校准的非线性和幻像校正之间有很强的一致性，但是使用非线性校正的心律和分流计算与没有背景校正的心律和分流计算相比，更接近幻像校正的测量值。但是，幻影校正的流也显示出与未校正流的最小差异。这些发现表明，在当前时代，更准确的相衬流量测量可能会限制对背景校正的需求。需要进一步研究儿童和先天性心脏病人群的临床影响和背景校正的最佳方法。