Measurement of cerebrospinal fluid oxygen partial pressure in humans using MRI

Abstract

Fluid-attenuated inversion recovery (FLAIR) images obtained during the administration of supplemental oxygen demonstrate a hyperintense signal within the cerebrospinal fluid (CSF) that is likely caused by T1 changes induced by paramagnetic molecular oxygen. Previous studies demonstrated a linear relationship between the longitudinal relaxation rate (R1 = 1/T 1) and oxygen content, which permits quantification of the CSF oxygen partial pressure (PcsfO2). In the current study, CSF T1 was measured at 1.5 T in the lateral ventricles, third ventricle, cortical sulci, and basilar cisterns of eight normal subjects breathing room air or 100% oxygen. Phantom studies performed with artificial CSF enabled absolute PcsfO2 quantitation. Regional PcsfO2 differences on room air were observed, from 65 ± 27 mmHg in the basilar cisterns to 130 ± 49 mmHg in the third ventricle. During 100% oxygen, PcsfO2 increases of 155 ± 45 and 124 ± 34 mmHg were measured in the basilar cisterns and cortical sulci, respectively, with no change observed in the lateral or third ventricles. P csfO2 measurements in humans breathing room air or 100% oxygen using a T1 method are comparable to results from invasive human and animal studies. Similar approaches could be applied to noninvasively monitor oxygenation in many acellular, low-protein body fluids. © 2005 Wiley-Liss, Inc.