Processed skin surface images acquired by acoustic impedance difference imaging using the ultrasonic interference method: a pilot study.

To clarify the potential of a novel system using the acoustic impedance difference imaging (AIDI) method for diagnosis of skin disorders, we used it on a coin and swine skin. An ultrasound wave with a central frequency of 20 MHz, emitted from a fused quartz rod with a diameter of 1.25 mm, was focused on the surface of the coin and skin samples. The difference in acoustic impedance was determined by the reflection-type interference-based acoustic impedance measurement method. The processed data were produced as greyscale images on which the maximum measured amplitudes were mapped. We applied the method to a coin. Swine skin, burned and covered with an acrylic sheet with a thickness of 0.2 mm (a few times the half-wavelength) to eliminate the undulations of the skin surface, was employed to obtain processed images from which undulation data were excluded. All the processed images obtained corresponded almost exactly with the magnified optical ones. In the processed images of swine skin, a marked difference was found after the burning procedure. The processed images obtained using the AIDI method reflected not only the undulations but also other information such as elasticity. In conclusion, our system using AIDI has the potential to become a useful modality for the diagnosis of skin disorders.