Noninvasive Quantification of Left-to-Right Shunt in Pediatric Patients (original) (raw)

Background —Blood flow can be quantified noninvasively by phase-contrast cine MRI (PC-MRI) in adults. Little is known about the feasibility of the method in children with congenital heart disease. Methods and Results —In 50 children (mean age 6.2 years, range 1.1 to 17.7 years) with an atrial- or ventricular-level shunt, blood flow rate in the great vessels was determined by PC-MRI, and the ratio of pulmonary to aortic flow (Q̇p/Q̇s) was compared with Q̇p/Q̇s by oximetry. We found a difference of 2% and a range of −20% to +26% (limits of agreement, mean±2 SD). In another 7 children with congenital heart disease but no cardiac shunting (mean age 7.9 years, range 1.3 to 13.5 years), Q̇p/Q̇s by PC-MRI was 1.02 (SD ±0.06). No difference between systemic venous and aortic flow volumes was found (range −17% to +20%, n=37). Blood flow through a secundum atrial septal defect as assessed by PC-MRI (n=24) overestimated the shunt compared with the difference between pulmonary and aortic flows....