CRP and rheumatoid arthritis: This was done by correlating CEUS parameters measured using both the semi-quantitative IACUS (International Arthritis Contrast Ultrasound Score) and the VueBox® quantification tool, with GSUS, power Doppler ultrasound (PDUS), and GLOESS parameters in RA patients who had been in clinical remission for at least 6 months [DAS28 4 variables (4v), C-reactive protein (CRP) < 2.6].