Compressed Sensing Sodium MRI in Cartilage at 7T: Preliminary Study

Guillaume Madelin¹, Gregory Chang¹, Alexej Jerschow², Ricardo Otazo¹, Ravinder R. Regatte¹

Quantitative sodium MRI is highly specific to the glycosaminoglycan content in cartilage and could be used to assess the biochemical degradation of cartilage in early stages of osteoarthritis. However, due to low sodium NMR sensitivity and its low concentration, sodium images need long acquisition times (15 to 25 min, respectively without and with fluid suppression) at 7T and are typically of low resolution. In this preliminary study, we show that compressed sensing can be applied to reconstruct undersampled sodium images and reduce the acquisition time by a factor of 2 at 7T without losing sodium quantification accuracy.