Measurement of acoustic parameters of single cell by ultrasound microscope

Recently, the biomechanics of cell has received attention because the study on the biomechanics will lead to development of diagnosis and treatment of cancer and arteriosclerosis. Most methods on the measurement of biomechanics require direct contact to the cell. Because the square of sound speed is proportional to the cell elasticity, non-contact measurement of sound speed with ultrasound microscopy can obtain the mechanical properties. In the present study, quantitative measurement of cell parameters such as thickness, sound speed, acoustic impedance, density, bulk modulus, attenuation and images of each parameter are successfully obtained. The transducer had 150 MHz center frequency and f-number of 0.88 and focal length of 3.8 mm. Pulse spectrum analysis was applied to calculate thickness and sound speed of the cells because the signal from a cell surface was not distinguished from the echo from the petri dish. This study may contribute measurement of cellular biomechanics.