Frequency-dependent attenuation in breast tissue characterization.

The aim of this study is to establish whether an index derived from the slope of the frequency-dependent ultrasonic attenuation can provide quantitative information on normal and pathological breast tissue. Ultrasonic measurements were performed by using pulsed transmitted ultrasound in the frequency range 2-8 MHz. Thirty-three specimens were selected for their probable pathologic classification, by macroscopic observation, before ultrasonic study, and subsequently histologically classified. Ultrasonic results suggest the possibility that the examined specimens fall into four groups: (1) fat, fibroadenoma, giant fibroadenoma, infiltrating ductal carcinoma, medullary carcinoma; (2) infiltrating lobular carcinoma, tubular carcinoma, scirrhous carcinoma; (3) fibrosis; (4) fibrofatty tissue, fibrocystic disease. Correlative morphological studies indicate that the employed index can classify breast tissues on the basis of their cellular and fibrous composition and the inhomogeneity of their structure.