DIrect EStimation of 17O MR ImageS (DIESIS) for CMRO2 Quantification in the Human Brain with Partial Volume Correction

Direct ¹⁷O-MRI enables quantification of cerebral metabolic rate of oxygen consumption (CMRO₂). The low MR sensitivity of the ¹⁷O nucleus prevents pixel-wise CMRO₂ quantification and the fast T₂^*≈2ms decay leads to partial volume artifacts. In this work the DIESIS method is proposed, which performs a direct least squares estimation of the ¹⁷O‑MR signal in image regions (parcels) obtained from coregistered ¹H data. CMRO₂ values of 1.38-1.87µmol/gtissue/min and 0.51-0.77µmol/gtissue/min were found with DIESIS in gray and white matter consistent with rates from ¹⁵O-PET studies. With DIESIS, CMRO₂ maps of high resolution can be reconstructed and partial volume artifacts can be reduced.