Abstract 14156: Assessment of Pulmonary Arterial Pressure in Children with Congenital Heart Disease by Velocity-Encoded Cine Magnetic Resonance Imaging
Background:Children with congenital heart disease (CHD) often exhibit increased pulmonary blood flow (Qp) and pulmonary hypertension. It has been recently reported that the maximal change in the flow rate during ejection (MCFR) obtained by velocity-encoded cine magnetic resonance imaging (VEC-MRI) reflects pulmonary arterial pressure (PAP) in adults. However, there are few reports regarding the usefulness of MCFR in assessing PAP in children. Whether the resting heart rate, which varies according to age, has an influence on MCFR needs to be clarified.
Methods:Thirty-four children with CHD (age, 0.3-15 years; median, 3.8 years) were examined. Qp and systemic blood flow (Qs) were determined by cardiac catheterization and VEC-MRI. The ratio of pulmonary-to systemic blood pressure (Pp/Ps) was determined by cardiac catheterization. The time-velocity and flow-volume curves obtained by VEC-MRI revealed the acceleration time (AcT), ejection time (ET), acceleration volume (AV), peak velocity (PV), and MCFR in the pulmonary arteries. These parameters were divided by the cardiac cycle length or its square root (determined by the Bland-Altman plot) for standardization. The children were divided into two groups according to Pp/Ps (high PAP group: Pp/Ps >0.25, n = 17; low PAP group: Pp/Ps <0.25, n = 17).
Results:Qp/Qs and Qs obtained by VEC-MRI strongly correlated with those obtained by catheterization (r = 0.891 and 0.832, respectively). Between the two groups, no significant difference was observed in AcT, ET, AcT/ET, AV, and PV; however, a significant difference was observed in MCFR (p < 0.001; Fig. 1). Furthermore, a significant correlation was observed between MCFR and Pp/Ps (r = 0.90, p < 0.001; Fig. 2).
Conclusions: This study clearly demonstrated that noninvasive VEC-MRI is useful for assessing not only blood flow but also PAP by referring to MCFR, irrespective of the resting heart rate in children with CHD.
- Magnetic resonance imaging
- Pulmonary hypertension
- Congenital heart disease
- Noninvasive cardiac imaging
- Pediatric cardiology
- © 2012 by American Heart Association, Inc.