Tissue Sound Velocity: m/s Density: kg/m3 Attn: dB/cm/MHz n B/A Water % Collagen % Fat % Protein % Bone 2900~4300 ~1700 ~13 N/A N/A 22~34 13~20 0 13~20 Blood 1540 1000 0.03 1.3 90 0 0 0 Brain 1470 1.034 0.32 1.38 ~5 72~85 0.03~0.34 8.6 6~11 FAT 1410-1479 952 0.6 10 100 Heart 1570~1585 ~1.3 1.02 7 63~79 0.4~2.6 3.6~21 15~19 Kidney 1560 1040 ~0.9 1.02 7 76~83 0.4~1.5 3.3~6.7 15~17 Liver 1553~1607 1060 0.6~0.13 1.02 7 67~80 0.18~1.1 3.7~10 17~21 Lung 300~1118 30~43 76~79 2~3 3~4 17~19 FAT 1410-1479 952 0.6 10 100 air 1500 1.2