Fig. 1
a Nuclear magnetic resonance tubes with different ratios of synovial fluid and blood. Blood percentage from left to right: 0%, 2.5%, 5%, 10%, 25%, 50%, 75%, and 100%. b Phantom setup: a cylindrical water-filled holder with six samples, horizontally placed in a 16-channel knee coil using a 3-T MRI system. The phantom was equipped with a fiberoptic thermometer (the asterisk in all images) and a heating system based on heat exchange between water in the heating system (black arrows) and the water or oil volume in the phantom. c Scan image from the T1 mapping sequence. For each tube, a region of interest was manually placed within the tube region (example in yellow). d Scan image from the T2 mapping sequence