Assessment of Pulmonary Arterial Pressure by Velocity-Encoded Cine Magnetic Resonance Imaging in Children With Congenital Heart Disease

Abstract

Background: Velocity-encoded cine magnetic resonance imaging (VEC-MRI) has recently been reported as effective for assessing not only pulmonary blood flow (Qp) but also pulmonary arterial pressure (PAP) in adults. However, there have been few reports on the usefulness of VEC-MRI for assessing PAP in children with congenital heart disease (CHD). Methods and Results:We evaluated 34 children with CHD. Qp and systemic blood flows (Qs) were determined by cardiac catheterization and VEC-MRI. The right-to-left Qp ratio (R/L) was measured by pulmonary perfusion scintigraphy and VEC-MRI. The pulmonary-to-systemic blood pressure ratio (Pp/Ps) was determined by cardiac catheterization. The acceleration time (AcT), ejection time (ET), peak velocity (PV), acceleration volume (AcV), and maximal change in flow rate during ejection (MCFR) in the pulmonary arteries, which were standardized by body surface area, were determined by VEC-MRI. The children were divided into 2 groups according to Pp/Ps. The Qs, R/L ratio and Qp/Qs obtained by VEC-MRI strongly correlated with those obtained by catheterization and scintigraphy. No significant differences in AcT, ET, AcT/ET, PV, or AcV were observed between the 2 groups. However, a significant difference was observed in MCFR. Furthermore, a significant correlation was observed between the MCFR and Pp/Ps. Conclusions:This study clearly demonstrated that VEC-MRI is useful for assessing not only blood flow, but also PAP, by referring to MCFR in children. (Circ J 2013; 77: 3015 -3022)

Assessment of Hemodynamics by Magnetic Resonance Imaging

“…Our results showed that there was an extremely good correlation between Qp/Qs values obtained using VEC-MRI and those obtained using oximetry with cardiac catheterization (Fig. 8.13) [26].…”

“…Our study on pediatric patients showed a good correlation between MCFR assessed using VEC-MRI and pulmonary arterial systolic pressure assessed using cardiac catheterization ( Fig. 8.18) [26]. BSA body surface area, sPAP systolic PAP, mPAP mean PAP, dPAP diastolic PAP, Qp/Qs the ratio of pulmonary to systemic blood flow, Pp/Ps the ratio of pulmonary to systemic blood pressure, Rp pulmonary arterial vascular resistance…”

MR phase-contrast imaging in pulmonary hypertension

“…27,62,63 Mousseaux et al 62 documented a strong correlation between PVR and the quotient of maximum change in flow rate during ejection by AccV ( r  = 0.89). Moreover, Sugimoto et al 64 found that the maximum change in flow rate during ejection, when normalized to the body surface area, was significantly higher in children with PH than in children without PH and correlated strongly with pulmonary-to-systemic blood pressure ratio in children with PH ( r  = 0.90); the parameters AT, ET, AT/ET, AccV and v peak revealed no significant differences between the PH and non-PH groups.…”

Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension: A review

“…Additionally, cardiac magnetic resonance imaging has also been used to assess pulmonary artery pressure measurements in children with congenital heart disease. Researchers found velocity encoded flow cardiac MRI images strongly correlated with right heart catheterization for systemic blood flow (QS), right to left pulmonary blood flow (QP) ratio and QP/QS ratio[ 47 ]. This suggests usefulness of cardiac MRI for pulmonary artery pressure measurement by using the standard SSFP cine imaging and phase contrast flow imaging.…”