Imaging data from the osmotic loading and real-time ultrasound system. (a) Histology of a typical articular cartilage sample. (b) A-mode echogram from an articular cartilage sample. The black arrow indicates the amplitude from the cartilage surface and the white arrow indicates the amplitude from the cartilage-bone interface. The amplitude recovery rate was calculated from the change in the cartilage surface amplitude from the shrinkage phase to the swelling phase. (c) M-mode image before osmotic loading. The gray levels indicate the amplitudes of the ultrasound signals. (d) Typical M-mode image in the shrinkage phase. (e) Typical M-mode image in the swelling phase.