Right and left ventricular function and flow quantification in pediatric patients with repaired tetralogy of Fallot using four-dimensional flow magnetic resonance imaging

Abstract

Background To assess the accuracy and reproducibility of right ventricular (RV) and left ventricular (LV) function and flow measurements in children with repaired tetralogy of Fallot (rTOF) using four-dimensional (4D) flow, compared with conventional two-dimensional (2D) magnetic resonance imaging (MRI) sequences. Methods Thirty pediatric patients with rTOF were retrospectively enrolled to undergo 2D balanced steady-state free precession cine (2D b-SSFP cine), 2D phase contrast (PC), and 4D flow cardiac MRI. LV and RV volumes and flow in the ascending aorta (AAO) and main pulmonary artery (MPA) were quantified. Pearson’s or Spearman’s correlation tests, paired t-tests, the Wilcoxon signed-rank test, Bland–Altman analysis, and intraclass correlation coefficients (ICC) were performed. Results The 4D flow scan time was shorter compared with 2D sequences (P < 0.001). The biventricular volumes between 4D flow and 2D b-SSFP cine had no significant differences (P > 0.05), and showed strong correlations (r > 0.90, P < 0.001) and good consistency. The flow measurements of the AAO and MPA between 4D flow and 2D PC showed moderate to good correlations (r > 0.60, P < 0.001). There was good internal consistency in cardiac output. There was good intraobserver and interobserver biventricular function agreement (ICC > 0.85). Conclusions RV and LV function and flow quantification in pediatric patients with rTOF using 4D flow MRI can be measured accurately and reproducibly compared to those with conventional 2D sequences.

The Functioning of the Frog’s Single Ventricle

“…• Amphibians such as the Xenopus Laevis have a single ventricle, both in terms of morphology and function, whereas children with functionally single ventricle typically have two ventricles albeit in a setting of one ventricle being severely hypoplastic • Our observations with flows measurements performed using echocardiography constitute another initial step towards a complete analysis of the function of the frog's single ventricle [62] • because of logistic reasons the echocardiographic measurements were performed at a room temperature of 22 • C, higher than the 17 • C, normal environmental temperature for frogs • Studies of the systemic and pulmonary flows distribution with the more modern methodologies of ECG-gated MRI, validated in small vessels in experimental as well as clinical studies could provide high quality of innovation and creativity for our translational research [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77] • We always have to be aware of the species-to-species differences…”