@article{ma_jiang_2020, title={Contrast-Enhanced Dual-Frequency Super-Harmonic Intravascular Ultrasound (IVUS) Imaging}, ISBN={["978-981-10-6306-0"]}, DOI={10.1007/978-981-10-6307-7_5}, journal={MULTIMODALITY IMAGING: FOR INTRAVASCULAR APPLICATION}, author={Ma, Jianguo and Jiang, Xiaoning}, year={2020}, pages={105–151} }
 @book{jiang_li_kim_ma_2017, title={High frequency piezo-composite micromachined ultrasound transducer array technology for biomedical imaging}, DOI={10.1115/1.860441}, abstractNote={in this monograph, the authors report the current advancement in high frequency piezoelectric crystal micromachined ultrasound transducers and arrays and their biomedical applications. piezoelectric ultrasound transducers operating at high frequencies (>20 mhz) are of increasing demand in recent years for medical imaging and biological particle manipulation involved therapy. The performances of transducers greatly rely on the properties of the piezoelectric materials and transduction structures, including piezoelectric coefficient (d), electromechanical coupling coefficient (k), dielectric permittivity (e) and acoustic impedance (Z). piezo-composite structures are preferred because of their relatively high electromechanical coupling coefficient and low acoustic impedance. a number of piezo-composite techniques have been developed, namely “dice and fill”, “tape-casting”, “stack and bond”, “interdigital phase bonding”, “laser micromachining” and “micro-molding”. however, these techniques are either difficult to achieve fine features or not suitable for manufacturing of high frequency ultrasound transducers (>20 mhz). The piezo-composite micromachined ultrasound transducers (pc-mUT) technique discovered over the last 10 years or so has demonstrated high performance high frequency piezo-composite ultrasound transducers. in this monograph, piezoelectric materials used for high frequency transducers is introduced first. Next, the benefits and theory of piezo composites is presented, followed by the design criteria and fabrication methods. Biomedical applications using pc-mUT and arrays will also be reported, in comparison with other ultrasound transducer techniques. The final part of this monograph describes challenges and future perspectives of this technique for biomedical applications. ASME_Bionano Monograph Jiang_FM.indd vi Manila Typesetting Company 08/29/2017 09:58PM ASME_Bionano Monograph Jiang_FM.indd vii Manila Typesetting Company 08/29/2017 09:58PM Downloaded From: http://asmedigitalcollection.asme.org on 10/21/2018 Terms of Use: http://www.asme.org/about-asme/terms-of-use Downloaded From: http://asmedigitalcollection.asme.org on 10/21/2018 Terms of Use: http://www.asme.org/about-asme/terms-of-use}, publisher={New York, NY, USA: ASME Press}, author={Jiang, X. and Li, S. and Kim, J. and Ma, J.}, year={2017} }
 @article{martin_lindsey_ma_nichols_jiang_dayton_2016, title={EX VIVO PORCINE ARTERIAL AND CHORIOALLANTOIC MEMBRANE ACOUSTIC ANGIOGRAPHY USING DUAL-FREQUENCY INTRAVASCULAR ULTRASOUND PROBES}, volume={42}, ISSN={["1879-291X"]}, DOI={10.1016/j.ultrasmedbio.2016.04.008}, abstractNote={The presence of blood vessels within a developing atherosclerotic plaque has been found to be correlated with increased plaque vulnerability and ensuing cardiac events, however, detection of coronary intraplaque neovascularization poses a significant challenge in the clinic. We describe here a new in vivo intravascular ultrasound imaging method using a dual-frequency transducer to visualize contrast flow in microvessels with high specificity. This method uses a specialized transducer capable of exciting contrast agents at a low frequency (5.5 MHz) while detecting their nonlinear superhamonics at a much higher frequency (37 MHz). In vitro evaluation of the approach was performed in a microvascular phantom to produce 3-D renderings of simulated vessel patterns and to determine image quality metrics as a function of depth. Furthermore, we describe the ability of the system to detect microvessels both ex vivo using porcine arteries and in vivo using the chorioallantoic membrane of a developing chicken embryo with optical confirmation. Dual-frequency contrast-specific imaging was able to resolve vessels similar in size to those found in vulnerable atherosclerotic plaques at clinically relevant depths. The results of this study add to the support for further evaluation and translation of contrast-specific imaging in intravascular ultrasound for the detection of vulnerable plaques in atherosclerosis.}, number={9}, journal={ULTRASOUND IN MEDICINE AND BIOLOGY}, author={Martin, K. Heath and Lindsey, Brooks D. and Ma, Jianguo and Nichols, Timothy C. and Jiang, Xiaoning and Dayton, Paul A.}, year={2016}, month={Sep}, pages={2294–2307} }
 @article{ma_steer_jiang_2015, title={An acoustic filter based on layered structure}, volume={106}, ISSN={0003-6951 1077-3118}, url={http://dx.doi.org/10.1063/1.4915100}, DOI={10.1063/1.4915100}, abstractNote={Acoustic filters (AFs) are key components to control wave propagation in multi-frequency systems. We present a design which selectively achieves acoustic filtering with a stop band and passive amplification at the high- and low-frequencies, respectively. Measurement results from the prototypes closely match the design predictions. The AF suppresses the high frequency aliasing echo by 14.5 dB and amplifies the low frequency transmission by 8.0 dB, increasing an axial resolution from 416 to 86 μm in imaging. The AF design approach is proved to be effective in multi-frequency systems.}, number={11}, journal={Applied Physics Letters}, publisher={AIP Publishing}, author={Ma, Jianguo and Steer, Michael B. and Jiang, Xiaoning}, year={2015}, month={Mar}, pages={111903} }
 @inproceedings{ma_li_wang_jiang_2015, title={Anti-matching design for wave isolation in dual frequency transducer for intravascular super-harmonic imaging}, DOI={10.1115/imece2014-38844}, abstractNote={Intravascular super-harmonic imaging of microvessels is expected to assist understanding of atherosclerotic cardiovascular disease. A dual frequency intravascular (IVUS) ultrasound transducer is a core component transmitting at low frequency and receiving high order harmonics. A significant challenge in developing high performance dual frequency IVUS transducers is the isolation of the high frequency ultrasound echoes from the low frequency element while keeping the low frequency transmission pressure. An anti-matching layer with low impedance and quarter wavelength thickness was designed based on wave propagation theory. In both KLM modeling and prototype validation, the anti-matching layer successfully suppressed the aliasing echo to less than −20 dB. Transmission pressure of the prototype transducer was still high enough for microbubble nonlinear responses. High resolution (<0.2 mm) and high CTR (>12 dB) image was generated from super-harmonic imaging, which elucidated the capability of the transducer for intravascular microvessel detection.}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition, 2014, vol 3}, author={Ma, J. G. and Li, S. B. and Wang, Z. C. and Jiang, X. N.}, year={2015} }
 @article{ma_martin_li_dayton_shung_zhou_jiang_2015, title={Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography}, volume={60}, ISSN={["1361-6560"]}, DOI={10.1088/0031-9155/60/9/3441}, abstractNote={Imaging of coronary vasa vasorum may lead to assessment of the vulnerable plaque development in diagnosis of atherosclerosis diseases. Dual frequency transducers capable of detection of microbubble super-harmonics have shown promise as a new contrast-enhanced intravascular ultrasound (CE-IVUS) platform with the capability of vasa vasorum imaging. Contrast-to-tissue ratio (CTR) in CE-IVUS imaging can be closely associated with low frequency transmitter performance. In this paper, transducer designs encompassing different transducer layouts, transmitting frequencies, and transducer materials are compared for optimization of imaging performance. In the layout selection, the stacked configuration showed superior super-harmonic imaging compared with the interleaved configuration. In the transmitter frequency selection, a decrease in frequency from 6.5 MHz to 5 MHz resulted in an increase of CTR from 15 dB to 22 dB when receiving frequency was kept constant at 30 MHz. In the material selection, the dual frequency transducer with the lead magnesium niobate-lead titanate (PMN-PT) 1–3 composite transmitter yielded higher axial resolution compared to single crystal transmitters (70 μm compared to 150 μm pulse length). These comparisons provide guidelines for the design of intravascular acoustic angiography transducers.}, number={9}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, author={Ma, Jianguo and Martin, K. Heath and Li, Yang and Dayton, Paul A. and Shung, K. Kirk and Zhou, Qifa and Jiang, Xiaoning}, year={2015}, month={May}, pages={3441–3457} }
 @article{lindsey_martin_dayton_ma_wang_jiang_2015, title={Dual-frequency intravascular ultrasound imaging of microbubble contrast agents: Ex vivo and in vivo demonstration}, ISSN={["1948-5719"]}, DOI={10.1109/ultsym.2015.0044}, abstractNote={Development of atherosclerotic plaques and related cardiac events are correlated with increased development of vasa vasorum, however, no currently-available diagnostic imaging method has been demonstrated effective at identifying vulnerable plaques. We present a new intravascular ultrasound (IVUS) imaging method using a dual-frequency transducer to visualize contrast flow in microvessels with high specificity. This method uses a specialized transducer capable of exciting contrast agents at a low frequency (5.5 MHz) and receiving superharmonic echoes at a much higher frequency (37 MHz). This dual-frequency transducer was used to image a cellulose micro-tube external to an ex vivo porcine artery and also using the chorioallantoic membrane of a developing chicken embryo. Using dual-frequency contrast-specific imaging, we were able to resolve vessels of a similar size to those found in vulnerable atherosclerotic plaques with clinically-relevant attenuation. The results of this study suggest contrast-specific intravascular ultrasound imaging for the detection of vulnerable plaques in atherosclerosis may provide additional diagnostic information.}, journal={2015 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)}, author={Lindsey, Brooks D. and Martin, K. Heath and Dayton, Paul A. and Ma, Jianguo and Wang, Zhuochen and Jiang, Xiaoning}, year={2015} }
 @article{li_ma_martin_choi_dayton_jiang_shung_zhou_2014, title={A Configurable Dual-Frequency Transmit/Receive System for Acoustic Angiography Imaging}, ISSN={["1948-5719"]}, DOI={10.1109/ultsym.2014.0180}, abstractNote={Acoustic angiography is a high-resolution imaging modality for small vascular structure. It utilizes the nonlinear backscatter of microbubble contrast agents (MCAs) to delineate blood vessels. In acoustic angiography, where MCAs are insonified with high rarefractional pressures at resonance frequency (6.5MHz), high-order harmonics (30 MHz) become more evident and can be utilized to produce high-resolution images for detecting small vascular structures. We developed a configurable dual-frequency system platform dedicated to acoustic angiography. The system consists of pulse generation, data acquisition and signal processing blocks. It is controlled by a field programmable gate array (FPGA), which enables flexible programming, and many on-board processing and stimulation modes. The system was shown to be capable of acoustic angiography as well as traditional B-mode imaging.}, journal={2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)}, author={Li, Yang and Ma, Jianguo and Martin, K. Heath and Choi, Hojong and Dayton, Paul A. and Jiang, Xiaoning and Shung, K. Kirk and Zhou, Qifa}, year={2014}, pages={731–733} }
 @article{ma_martin_dayton_jiang_2014, title={A preliminary engineering design of intravascular dual-frequency transducers for contrast-enhanced acoustic angiography and molecular imaging}, volume={61}, DOI={10.1109/tuffc.2014.6805699}, abstractNote={Current intravascular ultrasound (IVUS) probes are not optimized for contrast detection because of their design for high-frequency fundamental-mode imaging. However, data from transcutaneous contrast imaging suggests the possibility of utilizing contrast ultrasound for molecular imaging or vasa vasorum assessment to further elucidate atherosclerotic plaque deposition. This paper presents the design, fabrication, and characterization of a small-aperture (0.6 × 3 mm) IVUS probe optimized for high-frequency contrast imaging. The design utilizes a dual-frequency (6.5 MHz/30 MHz) transducer arrangement for exciting microbubbles at low frequencies (near their resonance) and detecting their broadband harmonics at high frequencies, minimizing detected tissue backscatter. The prototype probe is able to generate nonlinear microbubble response with more than 1.2 MPa of rarefractional pressure (mechanical index: 0.48) at 6.5 MHz, and is also able to detect microbubble response with a broadband receiving element (center frequency: 30 MHz, -6-dB fractional bandwidth: 58.6%). Nonlinear super-harmonics from microbubbles flowing through a 200-μm-diameter micro-tube were clearly detected with a signal-to-noise ratio higher than 12 dB. Preliminary phantom imaging at the fundamental frequency (30 MHz) and dual-frequency super-harmonic imaging results suggest the promise of small aperture, dual-frequency IVUS transducers for contrast-enhanced IVUS imaging.}, number={5}, journal={IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control}, author={Ma, J. G. and Martin, K. H. and Dayton, P. A. and Jiang, X. N.}, year={2014}, pages={870–880} }
 @article{czernuszcwicz_gallippi_wang_ma_jiang_2014, title={Acoustic radiation force (ARF) generation with a novel dual-frequency intravascular transducer.}, ISSN={["1948-5719"]}, DOI={10.1109/ultsym.2014.0569}, abstractNote={Atherosclerosis and coronary artery disease remain the leading cause of death in the US. Coronary plaque is visualized with intravascular ultrasound (IVUS) and is typically implemented with high center frequencies (>20 MHz) for superior spatial resolution. Coronary plaque characterization may be improved by implementing elasticity imaging techniques such as acoustic radiation force impulse (ARFI) imaging using IVUS transducers. In this work we propose to extend ARFI imaging to a novel, dual-frequency small-aperture transducer design that includes a low-frequency “pushing” element and a high-frequency “tracking” element. A 40 MHz element (0.6 mm × 0.6 mm) was integrated onto a 5 MHz element (0.6 mm × 3 mm). Both elements of the transducer were fabricated from single crystal PMN-PT and the whole transducer was mounted on a 20 gauge needle tip. ARF-induced motion from the low-frequency element was quantified using optical tracking methods in a translucent phantom (~8 kPa) containing embedded graphite microparticles. Displacements induced by ARF excitations with 300, 600, 900, and 1200 cycles (5 MHz, 190 V) were captured and compared to baseline. Median (inter-quartile range) peak displacements for 300, 600, 900, and 1200 cycles were 0.33 (0.27 - 0.39) μm, 0.72 (0.62 - 0.87) μm, 1.1 (1.0 - 1.3) μm, and 1.6 (1.43 - 1.75) μm, respectively. In another phantom, 40 MHz pulse/echo RF lines were captured to demonstrate backscatter sensitivity. The results of this study show that ARF generation and high-resolution tracking is feasible on a small-aperture transducer fit for IVUS implementation.}, journal={2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)}, author={Czernuszcwicz, Tomasz J. and Gallippi, Caterina M. and Wang, Zhuochen and Ma, Jianguo and Jiang, Xiaoning}, year={2014}, pages={2284–2287} }
 @article{wang_ma_jiang_martin_dayton_2014, title={An array transmitter for dual-frequency contrast enhanced intravascular ultrasound imaging}, ISSN={["1948-5719"]}, DOI={10.1109/ultsym.2014.0524}, abstractNote={Recent studies suggests that contrast ultrasound for molecular imaging or vasa vasorum (VV) assessment may be promising in identification of vulnerable plaques. However, conventional intravascular ultrasound (IVUS) transducers with frequency of 15 MHz - 60 MHz are not optimized for imaging with micro bubble contrast agents due to the ineffective micro bubble excitation at high frequencies and poor signal separation from tissue. This paper presents design and fabrication of a lateral mode transducer array with center frequency of 2 MHz for contrast enhanced IVUS (CE-IVUS) imaging, which can generate sufficient pressure to excite microbubbles more effectively and therefore could be used for dual-frequency microbubble superharmonic imaging, or `acoustic angiography'. Several commercial transducers with central frequency of 15 MHz, 20 MHz and 25 MHz were used as receivers to receive the contrast signal. In the contrast testing, the high frequency echo of the nonlinear response from microbubbles in a micro-tube with diameter of 0.2 mm was detected. The maximum contrast to noise ratio was 12.2 dB. The results show that superharmonic signals (over 9th harmonic) can be received; suggesting good resolution and signal separation in contrast enhanced IVUS imaging.}, journal={2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)}, author={Wang, Zhuochen and Ma, Jianguo and Jiang, Xiaoning and Martin, Karl Heath and Dayton, Paul A.}, year={2014}, pages={2104–2107} }
 @article{ma_jiang_martin_dayton_li_zhou_2014, title={Dual Frequency Transducers for Intravascular Ultrasound Super-harmonic Imaging and Acoustic Angiography}, ISSN={["1948-5719"]}, DOI={10.1109/ultsym.2014.0166}, abstractNote={Imaging of coronary vasa vasorum may lead to assessment of the vulnerable plaque development in diagnosis of atherosclerosis diseases. Intravascular ultrasound (IVUS) imaging transducers capable of detecting microvessels via nonlinear contrast imaging could provide valuable diagnostic information, however such transducers are not yet produced commercially. Dual-frequency transducers capable of detection of microbubble super-harmonics have shown promise as a new contrast-enhanced IVUS (CE-IVUS) platform. Contrast-to-tissue ratio (CTR) in CE-IVUS imaging can be closely associated with the low frequency transmitter performance. In this paper, multiple dual frequency IVUS transducers with different transmission frequencies (6.5 and 5 MHz) and different materials (PMN-PT single crystals and 1-3 composite) were developed and evaluated. All transducer structures were constructed with the 30 MHz high frequency reception element in front of the low frequency transmission element. Super-harmonic imaging was carried out using a tissue mimicking phantom. With similar peak negative pressures, the lower transmission frequency transducers generated higher CTR (23 dB for 5 MHz transmission). With similar input excitations, the PMN-PT 1-3 composite produced higher resolution (70 μm for 1-cycle burst excitation) than single crystal ones (> 150 μm). Dual frequency transducers with 5 MHz transmitters made of PMN-PT 1-3 composite are preferable in the CE-IVUS imaging.}, journal={2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)}, author={Ma, Jianguo and Jiang, Xiaoning and Martin, Karl H. and Dayton, Paul A. and Li, Yang and Zhou, Qifa}, year={2014}, pages={675–678} }
 @misc{martin_lindsey_ma_lee_li_foster_jiang_dayton_2014, title={Dual-Frequency Piezoelectric Transducers for Contrast Enhanced Ultrasound Imaging}, volume={14}, ISSN={["1424-8220"]}, DOI={10.3390/s141120825}, abstractNote={For many years, ultrasound has provided clinicians with an affordable and effective imaging tool for applications ranging from cardiology to obstetrics. Development of microbubble contrast agents over the past several decades has enabled ultrasound to distinguish between blood flow and surrounding tissue. Current clinical practices using microbubble contrast agents rely heavily on user training to evaluate degree of localized perfusion. Advances in separating the signals produced from contrast agents versus surrounding tissue backscatter provide unique opportunities for specialized sensors designed to image microbubbles with higher signal to noise and resolution than previously possible. In this review article, we describe the background principles and recent developments of ultrasound transducer technology for receiving signals produced by contrast agents while rejecting signals arising from soft tissue. This approach relies on transmitting at a low-frequency and receiving microbubble harmonic signals at frequencies many times higher than the transmitted frequency. Design and fabrication of dual-frequency transducers and the extension of recent developments in transducer technology for dual-frequency harmonic imaging are discussed.}, number={11}, journal={SENSORS}, author={Martin, K. Heath and Lindsey, Brooks D. and Ma, Jianguo and Lee, Mike and Li, Sibo and Foster, F. Stuart and Jiang, Xiaoning and Dayton, Paul A.}, year={2014}, month={Nov}, pages={20825–20842} }
 @article{ma_guo_wu_geng_jiang_2013, title={Design, Fabrication, and Characterization of a Single-Aperture 1.5-MHz/3-MHz Dual-Frequency HIFU Transducer}, volume={60}, ISSN={["1525-8955"]}, DOI={10.1109/tuffc.2013.2724}, abstractNote={High-intensity focused ultrasound (HIFU) treatment efficiency is critical in maximizing the hyperthermia and reducing the surgery time. In this paper, a single-aperture, 1.5 MHz/3 MHz dual-frequency HIFU transducer was designed, fabricated, and characterized for tissue ablation enhancement. Double PZT-2 layers were configured in serial and dual-frequency ultrasound waves can be concurrently generated by exciting one of the PZT-2 layers. Impulse responses from the prototype showed that the wave amplitudes at 1.5 and 3 MHz were about the same, and both are more than 12 dB larger than those of higher orders of harmonics. Tissue ablation tests demonstrated that higher temperature rise can be achieved with dual-frequency ultrasound than with single-frequency ablation at the same acoustic power.}, number={7}, journal={IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL}, author={Ma, Jianguo and Guo, Sijia and Wu, Di and Geng, Xuecang and Jiang, Xiaoning}, year={2013}, month={Jul}, pages={1519–1529} }
 @article{ma_wang_jiang_2013, title={Design, fabrication and test of a small aperture, dual frequency ultrasound transducer}, volume={8695}, ISSN={["1996-756X"]}, DOI={10.1117/12.2009716}, abstractNote={High resolution ultrasound medical imaging requires high frequency transducers, which usually are known with decreased penetration depth because of high loss in two-way-loop at high frequencies. To obtain high resolution imaging at large depth, a dual frequency transducer was designed for contrast imaging. Specifically, a 35 MHz receiving transducer with aperture of 0.6 mm x 0.6 mm was integrated into a 6.5 MHz transmitting transducer with aperture of 0.6 mm x 3 mm. High pressure ultrasound at low frequency was generated by the transducer to excited microbubbles in tissue. High frequency component of the nonlinear response from microbubbles were received by the 35 MHz transducer for high resolution imaging at a relatively large depth. The prototyped transducer showed the ability of transmitting about 2 MPa pressure at 6.5 MHz, under an input of 5-cycle burst at 250 Vpp, which is high enough to generate nonlinear oscillation of microbubbles. The pulse-echo test showed that the -6 dB bandwidth of the 35 MHz transducer is 34.4% and the loop sensitivity is -38.3 dB. The small aperture, dual frequency ultrasound transducers developed in this paper are promising for high resolution ultrasound medical imaging.}, journal={HEALTH MONITORING OF STRUCTURAL AND BIOLOGICAL SYSTEMS 2013}, author={Ma, Jianguo and Wang, Zhuochen and Jiang, Xiaoning}, year={2013} }
 @inproceedings{ma_jiang_martin_dayton, title={Small aperture, dual frequency ultrasound transducers for intravascular contrast imaging}, booktitle={2013 ieee international ultrasonics symposium (ius)}, author={Ma, J. G. and Jiang, X. N. and Martin, K. H. and Dayton, P. A.}, pages={761–764} }