3He-MRI-based measurements of intrapulmonary p(O2) and its time course during apnea in healthy volunteers: First results, reproducibility, and technical limitations

Abstract

We applied a recently developed method of following the time course of the intrapulmonary oxygen partial pressure p(O2)(t) during apnea by 3He MRI to healthy volunteers. Using two imaging series with different interscan times during two breathholds (double acquisition technique), relaxation of 3He due to paramagnetic oxygen and depolarization by RF pulses were discriminated. In all four subjects, the temporal evolution of p(O2) was found to be linear, and was described by an initial partial pressure p0 and a decrease rate R. Also, regional differences of both p0 and R were observed. A correlation between p0 and R was apparent. Finally, we discuss limitations of the double acquisition approach. Copyright (C) 2000 John Wiley and Sons, Ltd.