An anthropomorphic ultrasound breast phantom containing intermediate-sized scatterers.

An anthropomorphic breast phantom, built from materials which mimic tissue parenchymae with respect to attenuation coefficients, speeds of sound, densities and backscatter levels, is described in detail. One of the outstanding features of the phantom is that 30% of the volume of the glandular region consists of tissue-mimicking fat, the remainder being tissue-mimicking glandular (non-adipose) tissue. The presence of these tissue-mimicking fat globules should cause ultrasound beam distortions similar to those found in clinical scans of the breasts of younger women. Halliwell (1977) has presented direct evidence for such beam distortions in real breasts. Other tissues simulated in the phantom are: skin, subcutaneous and retromammary fat, Cooper's ligaments, ducts and (abnormal)masses. The potential areas of usefulness of the phantom are: aiding in the development of more effective ultrasound imaging machines, discovering-- or verifying the causes of--various artifacts in breast imaging, routine testing of instruments being used clinically for breast imaging, and training of ultrasonographers. Ultrasound images of the phantom, made using three different instruments, are displayed and discussed.