Evaluación del tracto de salida del ventrículo derecho mediante resonancia magnética con flujo 4D en pacientes sometidos a recambio valvular pulmonar transcatéter / 4D flow magnetic resonance imaging to assess right ventricular outflow tract in patients undergoing transcatheter pulmonary valve replacement

Introducción y objetivos: La resonancia magnética (RM) con flujo 4D suele utilizarse para evaluar el ventrículo derecho y las arterias pulmonares antes del implante percutáneo de la válvula pulmonar (IPVP). Como el IPVP está limitado por el tamaño del tracto de salida del ventrículo derecho (TSVD), se necesita medirlo con precisión para planificar la intervención. El objetivo del presente estudio es comparar diferentes modalidades de RM con la medición invasiva del TSVD con balón.MétodosEstudio unicéntrico prospectivo de pacientes sometidos a IPVP por insuficiencia pulmonar aislada evaluada mediante RM con flujo 4D, precesión libre en estado estacionario/gradiente eco 3D (3D SSFP/GRE) y angiografía por RM con contraste. La medición con balón se consideró la referencia.ResultadosSe incluyó a 23 adultos (media de edad, 38,4±12,5 años). En 18 pacientes el IPVP fue exitoso. El diámetro medio del TSVD más pequeño fue de 25,4±4,3 mm medido con balón y 25,6±3,8 mm y 21,8±3,6 mm por RM con flujo 4D en sístole y diástole respectivamente. Comparados con los medidos con balón, los diámetros de TSVD se correlacionaron mejor cuando se estimaron mediante RM con flujo 4D sistólico (r=0,89; p<0,001) que mediante RM con flujo 4D diastólico (r=0,71; p<0,001), angiografía por R; 3D con contraste (r=0,73; p<0,001) o 3D SSFP/GRE (r=0,50; p=0,04), y no se correlacionaron de manera significativa cuando se realizaron en 2D en diástole o sístole. La diferencia media entre la RM con flujo 4D sistólico y la medición con balón fue de 0,2 mm (IC95%, –3,5 a 3,9 mm), en tanto que con las otras técnicas fue mayor.ConclusionesAdemás de la cuantificación de la insuficiencia de la válvula pulmonar, la RM con flujo 4D permite una estimación fiable de los diámetros del TSVD, sobre todo en sístole, lo que es fundamental antes de planificar el IPVP. (AU)

Introduction and objectives: Magnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiogram to balloon sizing of RVOT.MethodsSingle-centre prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiogram. Balloon sizing was considered as the reference.ResultsA total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<0.001) than by diastolic 4D flow MRI (r=0.71, P<0.001), 3D contrast magnetic resonance angiography (r=0.73; P<.001) and 3D SSFP/GRE (r=0.50; P=.04) and not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2mm (95%CI, –3.5 to 3.9 mm), whereas it was wider with other techniques.ConclusionsBeyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI. (AU)

4D flow magnetic resonance imaging to assess right ventricular outflow tract in patients undergoing transcatheter pulmonary valve replacement.

INTRODUCTION AND OBJECTIVES: Magnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiography to balloon sizing of RVOT. METHODS: Single-center prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiography. Balloon sizing was considered as the reference. RESULTS: A total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3 mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<.001) than by diastolic 4D flow MRI (r=0.71, P <.001), 3D contrast magnetic resonance angiography (r=0.73; P <.001) and 3D SSFP/GRE (r=0.50; P=.04) and was not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2 mm (95%CI, -3.5 to 3.9 mm), whereas it was wider with other techniques. CONCLUSIONS: Beyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.