Gary R. Frank

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We propose and characterize oil-in-gelatin dispersions that approximate the dispersive dielectric properties of a variety of human soft tissues over the microwave frequency range from 500 MHz to 20 GHz. Different tissues are mimicked by selection of an appropriate concentration of oil. The materials possess long-term stability and can be employed in(More)
Tissue-mimicking phantoms and an automated system have been developed for testing the resolution performance of ultrasound scanners by determining detectability of low to higher contrast spherical lesions over the entire depth of field. Axial, lateral and elevational resolutions are accounted for simultaneously and equally. Tissue-mimicking spherical(More)
This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques(More)
A ten-month study is presented of materials for use in heterogeneous elastography phantoms. The materials consist of gelatin with or without a suspension of microscopic safflower oil droplets. The highest volume percent of oil in the materials is 50%. Thimerosal acts as a preservative. The greater the safflower oil concentration, the lower the Young's(More)
OBJECTIVE To test the spatial accuracy of coordinates generated from magnetic resonance imaging (MRI) scans, using the Brown-Roberts-Wells head frame and localizer system (Radionics, Inc., Burlington, MA). METHODS An anthropomorphic head phantom, consisting of a two-dimensional lattice of acrylic spheres (4-mm diameter) spaced 10 mm apart and embedded in(More)
Magnetic particles are versatile imaging agents that have found wide spread applicability in diagnostic, therapeutic, and rheology applications. In this study, we demonstrate that mechanical waves generated by a localized inclusion of magnetic nanoparticles can be used for assessment of the tissue viscoelastic properties using magnetomotive optical(More)
Elastography is an emerging imaging modality that allows noninvasive imaging of tissue stiffness changes and stiffness values associated with pathology or as a result of therapy. However, many currently used systems for elastography rely on a fixed geometry transducer and compressor system for imaging. This configuration is disadvantageous for imaging(More)
This paper evaluates the performance of a level set algorithm for segmenting the endocardium in short-axis ultrasound images. The evaluation is carried out using an anthropomorphic ultrasound phantom. Details of the phantom design, including comparison of the ultrasound parameters with in-vitro measurements, are included. In addition to measuring(More)
Tissue-mimicking phantoms and software for quantifying the ability of human observers to detect small low-echo spheres as a function of depth have been developed. Detectability is related to the imager's ability to delineate the boundary of a 3-D object such as a spiculated tumor. The phantoms accommodate a broad range of transducer shapes and sizes. Three(More)
PURPOSE Quantitative ultrasound based approaches such as attenuation slope estimation can be used to determine underlying tissue properties and eventually used as a supplemental diagnostic technique to B-mode imaging. The authors investigate the impact of backscatter intensity and frequency dependence variations on the attenuation slope estimation accuracy.(More)