@article{sanders_biliroglu_newsome_adelegan_yamaner_dayton_oralkan_2022, title={A Handheld Imaging Probe for Acoustic Angiography With an Ultrawideband Capacitive Micromachined Ultrasonic Transducer (CMUT) Array}, volume={69}, ISSN={["1525-8955"]}, url={https://doi.org/10.1109/TUFFC.2022.3172566}, DOI={10.1109/TUFFC.2022.3172566}, abstractNote={This article presents an imaging probe with a 256-element ultrawideband (UWB) 1-D capacitive micromachined ultrasonic transducer (CMUT) array designed for acoustic angiography (AA). This array was fabricated on a borosilicate glass wafer with a reduced bottom electrode and an additional central plate mass to achieve the broad bandwidth. A custom 256-channel handheld probe was designed and implemented with integrated low-noise amplifiers and supporting power circuitry. This probe was used to characterize the UWB CMUT, which has a functional 3-dB frequency band from 3.5 to 23.5 MHz. A mechanical index (MI) of 0.33 was achieved at 3.5 MHz at a depth of 11 mm. These promising measurements are then combined to demonstrate AA. The use of alternate amplitude modulation (aAM) combined with a frequency analysis of the measured transmit signal demonstrates the suitability of the UWB CMUT for AA. This is achieved by measuring only a low level of unwanted high-frequency harmonics in both the transmit signal and the reconstructed image in the areas other than the contrast bubbles.}, number={7}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Sanders, Jean L. and Biliroglu, Ali Onder and Newsome, Isabel G. and Adelegan, Oluwafemi J. and Yamaner, Feysel Yalcin and Dayton, Paul A. and Oralkan, Omer}, year={2022}, month={Jul}, pages={2318–2330} }
 @article{yang_cherin_yin_newsome_kierski_pang_carnevale_dayton_foster_demore_2021, title={Characterization of an Array-Based Dual-Frequency Transducer for Superharmonic Contrast Imaging}, volume={68}, ISSN={["1525-8955"]}, DOI={10.1109/TUFFC.2021.3065952}, abstractNote={Superharmonic imaging with dual-frequency imaging systems uses conventional low-frequency ultrasound transducers on transmit, and high-frequency transducers on receive to detect higher order harmonic signals from microbubble contrast agents, enabling high-contrast imaging while suppressing clutter from background tissues. Current dual-frequency imaging systems for superharmonic imaging have been used for visualizing tumor microvasculature, with single-element transducers for each of the low- and high-frequency components. However, the useful field of view is limited by the fixed focus of single-element transducers, while image frame rates are limited by the mechanical translation of the transducers. In this article, we introduce an array-based dual-frequency transducer, with low-frequency and high-frequency arrays integrated within the probe head, to overcome the limitations of single-channel dual-frequency probes. The purpose of this study is to evaluate the line-by-line high-frequency imaging and superharmonic imaging capabilities of the array-based dual-frequency probe for acoustic angiography applications in vitro and in vivo. We report center frequencies of 1.86 MHz and 20.3 MHz with −6 dB bandwidths of 1.2 MHz (1.2–2.4 MHz) and 14.5 MHz (13.3–27.8 MHz) for the low- and high-frequency arrays, respectively. With the proposed beamforming schemes, excitation pressure was found to range from 336 to 458 kPa at its azimuthal foci. This was sufficient to induce nonlinear scattering from microbubble contrast agents. Specifically, in vitro contrast channel phantom imaging and in vivo xenograft mouse tumor imaging by this probe with superharmonic imaging showed contrast-to-tissue ratio improvements of 17.7 and 16.2 dB, respectively, compared to line-by-line micro-ultrasound B-mode imaging.}, number={7}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Yang, Jing and Cherin, Emmanuel and Yin, Jianhua and Newsome, Isabel G. and Kierski, Thomas M. and Pang, Guofeng and Carnevale, Claudia A. and Dayton, Paul A. and Foster, F. Stuart and Demore, Christine E. M.}, year={2021}, month={Jul}, pages={2419–2431} }
 @article{newsome_kierski_pang_yin_yang_cherin_foster_carnevale_demore_dayton_2021, title={Implementation of a Novel 288-Element Dual-Frequency Array for Acoustic Angiography: In Vitro and In Vivo Characterization}, volume={68}, ISSN={["1525-8955"]}, DOI={10.1109/TUFFC.2021.3074025}, abstractNote={Acoustic angiography is a superharmonic contrast-enhanced ultrasound imaging method that produces high-resolution, 3-D maps of the microvasculature. Previous acoustic angiography studies have used twoelement, annular,mechanicallyactuated transducers(called “wobblers”) to image microvasculature in preclinical tumor models with high contrast-to-tissue ratio and resolution, but these earlywobbler transducerscould not achieve the depth and sensitivity required for clinical acoustic angiography. In this work, we present a system for performing acoustic angiography with a novel dual-frequency(DF) transducer—a coaxially stacked DF array (DFA). We evaluate the DFA system bothin vitro andin vivo and demonstrate improvements in sensitivity and imaging depth up to 13.1 dB and 10 mm, respectively, compared with previous wobbler probes.}, number={8}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Newsome, Isabel G. and Kierski, Thomas M. and Pang, Guofeng and Yin, Jianhua and Yang, Jing and Cherin, Emmanuel and Foster, F. Stuart and Carnevale, Claudia A. and Demore, Christine E. M. and Dayton, Paul A.}, year={2021}, month={Aug}, pages={2657–2666} }
 @misc{newsome_dayton_2020, title={VISUALIZATION OF MICROVASCULAR ANGIOGENESIS USING DUAL-FREQUENCY CONTRAST-ENHANCED ACOUSTIC ANGIOGRAPHY: A REVIEW}, volume={46}, ISSN={["1879-291X"]}, DOI={10.1016/j.ultrasmedbio.2020.06.009}, abstractNote={Cancerous tumor growth is associated with the development of tortuous, chaotic microvasculature, and this aberrant microvascular morphology can act as a biomarker of malignant disease. Acoustic angiography is a contrast-enhanced ultrasound technique that relies on superharmonic imaging to form high-resolution 3-D maps of the microvasculature. To date, acoustic angiography has been performed with dual-element transducers that can achieve high contrast-to-tissue ratio and resolution in pre-clinical small animal models. In this review, we first describe the development of acoustic angiography, including the principle, transducer design, and optimization of superharmonic imaging techniques. We then detail several preclinical applications of this microvascular imaging method, as well as the current and future development of acoustic angiography as a pre-clinical and clinical diagnostic tool.}, number={10}, journal={ULTRASOUND IN MEDICINE AND BIOLOGY}, author={Newsome, Isabel G. and Dayton, Paul A.}, year={2020}, month={Oct}, pages={2625–2635} }