Characterization and differentiation of two mammary tumors using parametric imaging with ultrasound

Abstract

Two kinds of solid tumors were acquired and scanned in vivo ultrasonically. The first tumor series (fibroadenoma) was acquired from tumors that developed spontaneously in rats. The second tumor series was acquired by culturing a carcinoma cell line (4T1-MMT) and injecting the cells into Balb/c mice. The scatterer properties (average scatterer diameter and acoustic concentration) were estimated using a Gaussian form factor from the backscattered ultrasound measured from both kinds of tumors. Parametric images of tumors were constructed utilizing estimated scatterer properties for regions of interest inside the tumors and surrounding normal tissues. The average scatterer diameter and acoustic concentration for the fibroadenomas were estimated at 107±14 micrometers and 15.2±5 dB (mm−3), respectively. The average scatterer diameter and acoustic concentration for the carcinomas was estimated at 30±4.6 micrometers and 10.3±6.9 dB (mm−3), respectively. A comparison with light microscopic evaluations of the fibroadenomas showed cellular structures around 100 micrometers in size, and carcinomas showed cell nuclei with an average size of 12.5 micrometers in diameter (the total cellular size ranging from 50% to 200% larger than the nucleus size). [Work supported by NIH F32 CA96419 to MLO and by the University of Illinois Research Board.]