4D flow vs. 2D cardiac MRI for the evaluation of pulmonary regurgitation and ventricular volume in repaired tetralogy of Fallot: a retrospective case control study

AbstractLengthy exams and breath-holding limit the use of pediatric cardiac MRI (CMR). 3D time-resolved flow MRI (4DF) is a free-breathing, single-sequence exam that obtains magnitude (anatomic) and phase contrast (PC) data. We compare the accuracy of gadobenate dimeglumine-enhanced 4DF on a 1.5  T magnet to 2D CMR in children with repaired tetralogy of Fallot (rTOF) to measure pulmonary net flow (PNF) as a reflection of pulmonary regurgitation, forward flow (FF) and ventricular volumetry. Thirty-four consecutive cases were included. 2D PCs were obtained at the valve level. Using 4DF, we m easured PNF at the valve and at the main and branch pulmonary arteries. PNF measured at the valve by 4DF demonstrated the strongest correlation (r = 0.87, p <  0.001) and lowest mean difference (3.5 ± 9.4 mL/beat) to aortic net flow (ANF). Semilunar FF and stroke volume of the respective ventricle demonstrated moderate-strong correlation by 4DF (r = 0.66–0.81, p <  0.001) and strong correlation by 2D (r = 0.81–0.84, p <  0.001) with similar correlations and mean differences between techniques (p >  0.05). Ventricular volumes correlated strongly between 2D and 4DF (r = 0.75–0.96, p <  0.001), though 4DF overestimated right ventricle volumes by 11.8–19.2 mL/beat. Inter-rater reliability was excellent for 2D and 4DF volumetry (ICC = 0.91–0.99). Ejection fraction moderately correlated (r = 0.60–0.75, p <  0.00...
Source: The International Journal of Cardiovascular Imaging - Category: Radiology Source Type: research