Abstract #1925

Accuracy and Precision of MR Blood Oximetry Based on the Long Paramagnetic Cylinder Approximation of Large Vessels

Michael C. Langham¹, Jeremy Magland¹, Charles L. Epstein², Thomas F. Floyd³, Felix W. Wehrli¹

¹Radiology, University of Pennsylvania, Philadelphia, PA, USA; ²Mathematics, University of Pennsylvania, Philadelphia, PA, USA; ³Anesthesiology and Critical Care, Universityy of Pennsylvanis, Philadelphia, PA, USA

The accuracy and precision of MR susceptometry-based oximetry was investigated theoretically on the basis of an analytical expression for the arbitrarily oriented cylinder, as well as experimentally in phantoms and in vivo in the femoral artery and vein at 3T field strength. Hemoglobin saturation was measured at successive vessel segments, differing in geometry but constant blood oxygen saturation levels, as a means to evaluate measurement consistency. Reproducibility of in vivo HbO₂ quantification was on the order of 5% in the femoral vessels and the data indicate that non-circularity, although corrigible, can be ignored even at 30^o with tilt correction alone.