Compensation of Respiration-Induced Off-Resonance in Real-Time Spiral k-t BLAST Imaging

Holger Eggers¹

Free breathing leads not only to direct motion artifacts in abdominal real-time imaging, but also to respiration-induced field inhomogeneity artifacts. Their compensation would normally require a dynamic field mapping and a complex off-resonance correction. In this work, a simple, approximate approach is proposed for this purpose instead and is demonstrated in real-time spiral k-t BLAST imaging. It essentially involves a derivation of resonance frequency offsets from phase variations in the low frequency k-space samples of the imaging data and a subsequent, corresponding demodulation of the imaging data before their reconstruction for each receive coil element.