Free-breathing hepatic Oxygen Extraction Fraction (OEF) mapping using radial GESSE

Motivation: Non-invasive hepatic oxygenation mapping has been limited to single slice and single breath-hold. Goal(s): Multi-slice mapping of hepatic oxygenation in free-breathing is needed. Approach: In this study, hepatic oxygen extraction fraction (OEF) was measured using a radial gradient-echo sampling of spin-echo (rGESSE) sequence to cover multiple liver slices and be robust against respiratory motion. For OEF analysis, a feedforward artificial neural network (ANN) was used. Results: This study demonstrates the feasibility of radial GESSE to measure hepatic OEF. Impact: The feasibility of free-breathing liver OEF mapping using rGESSE was investigated. Further improvement of the quantification, possibly using measured macroscopic field inhomogeneities may be needed.