In vivo MRI measurement of blood oxygen saturation in children with congenital heart disease.

摘要

OBJECTIVE: The purpose of this prospective study was to measure in vivo blood oxygen saturation (O2) by MRI in children with congenital heart disease (CHD) using population-based values for T2O (T2 signal decay of fully oxygenated blood) and K (a parameter representing the deoxyhemoglobin effect) and compare the O2 with direct cardiac catheterization measurements. BACKGROUND: MRI can determine O2 using in vivo measurement of signal decay (T2) and an in vitro calibration curve relating T2 and O2, based on the equation: 1/T2 = 1/T2O + K(1-O2/100)2. Recent studies have correlated the T2/O2 in children with CHD with the adult calibration statistics. METHODS: A total of ten children (five male, five female) with single ventricle CHD (median age 4.8 months, range 2 months to 4.4 years) undergoing cardiac catheterization were included in the study. The blood T2 measurements for each patient were performed in a 1.5 T GE CV scanner. The O2 was then calculated based on the equation using values of T2O determined from individual hematocrits, and a population average value of K derived for children. The O2 values were compared with direct O2 measurements from cardiac catheterization. RESULTS: The O2 values by MRI were strongly correlated with direct cardiac catheterization measurements (R = 0.825; P < 0.001). CONCLUSION: The study indicates that the noninvasive measurement of O2 by MRI can accurately measure oxygen saturation in children with complex CHD.