Multiple tissue parameters are useful for early breast cancer detection and diagnosis. Ultrasound tomography is a new, important imaging modality for our Computerized Ultrasound Risk Evaluation (CURE) prototype, which employs a ring transducer array to scan the whole breast in a water tank. We use our bent-ray time-of-flight ultrasound tomography to reconstruct sound speeds of breasts with different densities. In addition, we develop an ultrasound attenuation reconstruction method based on complex-signal energy ratios. We apply our reconstruction techniques to in vitro and in vivo breast data acquired using the CURE device. Our reconstruction results demonstrate that CURE has great potential to reliably measure multiple mass characteristics by combining sound-speed, attenuation and reflection images.