Ultrasound phantom using thin wires for the depiction of calcification - Comparison of cross-sections of wire targets and mass targets -

We report on a technique to construct an ultrasound calcification phantom using wires. Employment of the proper angle of the measurement plane to a wire target can adjust its effective size to that of a mass target. To acquire this angle of the measurement plane we compared the scattering cross-sections of 0.2, 0.1, 0.05 and 0.03 mm diameter copper wires, and copper cylinders that are 0.2 and 0.1 mm in size. The experiments were conducted using a commercial ultrasonographic device with a 7.5 MHz linear array probe. The scattering cross-section of a wire is severely reduced as the angle of the measurement plane to that wire decreases. At a depth of 2 cm the scattering cross-sections of the 0.2 and 0.1 mm copper cylinders are equivalent to the scattering cross-section of a 0.1 mm diameter copper wire, when the measurement plane angles to the wire are 87.6 and 87.0 degrees for the 0.2 and 0.1 mm copper cylinders, respectively. This result indicated that the employment of the proper angle of the measurement plane can adjust the effective size of a wire target to the size of a mass target, and consequently fulfills the requirements for use as a calcification phantom.