High Definition Ultrasound for Mammography Abstract We propose to develop High Definition Ultrasound (HD-US) based on a hemispherical synthetic aperture and backscattered sonic waves. This configuration will produce direct three-dimensional maps of ultrasound reflectivity of breast tissues, and will display higher signal-to-noise, reduced speckle and greater spatial resolution compared to ultrasound arrays based on linear or curved planar sampling apertures. Our prototype hemispherical array consists of four interdigitated sub-arrays, each having 128 discrete elements. Currently, this array is used to capture 3D photoacoustic images of the whole breast using a spiral scanning strategy to increase the field of view sufficiently to perform whole-breast screening - PhotoAcoustic Mammography (PAM). In Phase I of this work, we will add a multiplexed pulser, pulse sequencer and T/R switches to capture ultrasound reflectivity data sufficient to form a 3D ultrasound image using the same reconstruction strategy used in PAM. Full 3D image acquisition will take 3.4 minutes, the same as currently used for PAM data collection. Spatial resolution and low contrast detectability will be quantified using anthropomorphic phantoms. In Phase II, HD-US will be combined with PAM to produce 3D images of soft tissue and microcalcifications. The 3D images will be co-registered with the PAM images of hemoglobin distribution in the breast using a single hemispherical transducer array.
We propose to develop a new type of ultrasound imaging device that will produce three-dimensional images of soft tissue and microcalcifications in the breast. This new scanner will be able to visualize subtler variations in breast tissue with better detail than existing breast ultrasound. When combined with x-ray or photoacoustic mammography, we anticipate that such images will improve a doctor's ability to detect breast cancer.