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Yu H, Zheng S, Wang C, Xing J, Li L. Novel anti-VEGFR2 antibody-conjugated nanobubbles for targeted ultrasound molecular imaging in a rabbit VX2 hepatic tumor model. J Mater Chem B 2023; 11:10956-10966. [PMID: 37942841 DOI: 10.1039/d3tb01718d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Nanobubbles (NBs), as ultrasound contrast agents, possess the potential for clinical applications in targeted ultrasound molecular imaging due to their small diameters and the specific molecular markers attached. Previous research studies mainly focused on the tumor-specific recruitment capability or drug carriers based on subcutaneous tumor models. In clinical trials, orthotopic tumor models are considered more clinically relevant and better predictive models for assessing drug efficacy compared to standard subcutaneous models. Here, we first prepared uniform-sized NBs with a soft chitosan-lipid membrane containing perfluoropropane gas and then anti-VEGFR2 antibodies were incorporated into NB membranes in order to achieve targeting ability toward tumor angiogenesis. The results of physicochemical characterization (the average size of 260.9 ± 3.3 nm and a PDI of 0.168 ± 0.036, n = 3) indicated that the targeted nanobubbles (tNBsv) have a spherical morphology and a vacant core. In vitro experiments found that the contrast enhancement abilities of tNBsv are similar to those of commercial SonoVue. In in vivo experiments, the orthotopic model of the rabbit VX2 hepatic tumor was used to evaluate the targeted binding ability of tNBsv toward tumor angiogenesis. Ultrasound sonograms revealed that tNBsv achieved the peak intensity of ultrasound imaging enhancement in the region of peripheral vasculature of VX2 tumors over non-targeted NBs or SonoVue, and the imaging time was longer than that of the other two. Ex vivo fluorescence imaging and examination using a confocal laser scanning microscope further verified that tNBsv were capable of binding to tumor angiogenesis. These results from our studies suggested that tNBsv are useful to develop an ultrasound imaging probe to evaluate anti-angiogenic cancer therapy by monitoring tumor angiogenesis.
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Affiliation(s)
- Houqiang Yu
- Department of Mathematics and Statistics, Hubei University of Science and Technology, Xianning 437100, P. R. China
| | - Shuanghua Zheng
- School of Biomedical Engineering and Imaging, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, P. R. China.
| | - Cai Wang
- School of Biomedical Engineering and Imaging, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, P. R. China.
| | - Jun Xing
- School of Biomedical Engineering and Imaging, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, P. R. China.
| | - Ling Li
- School of Biomedical Engineering and Imaging, Xianning Medical College, Hubei University of Science and Technology, Xianning 437100, P. R. China.
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Zhao X, Wright A, Goertz DE. An optical and acoustic investigation of microbubble cavitation in small channels under therapeutic ultrasound conditions. ULTRASONICS SONOCHEMISTRY 2023; 93:106291. [PMID: 36640460 PMCID: PMC9852793 DOI: 10.1016/j.ultsonch.2023.106291] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/22/2022] [Accepted: 01/04/2023] [Indexed: 06/04/2023]
Abstract
Therapeutic focused ultrasound in combination with encapsulated microbubbles is being widely investigated for its ability to elicit bioeffects in the microvasculature, such as transient permeabilization for drug delivery or at higher pressures to achieve 'antivascular' effects. While it is well established that the behaviors of microbubbles are altered when they are situated within sufficiently small vessels, there is a paucity of data examining how the bubble population dynamics and emissions change as a function of channel (vessel) diameter over a size range relevant to therapeutic ultrasound, particularly at pressures relevant to antivascular ultrasound. Here we use acoustic emissions detection and high-speed microscopy (10 kframes/s) to examine the behavior of a polydisperse clinically employed agent (Definity®) in wall-less channels as their diameters are scaled from 1200 to 15 µm. Pressures are varied from 0.1 to 3 MPa using either a 5 ms pulse or a sequence of 0.1 ms pulses spaced at 1 ms, both of which have been previously employed in an in vivo context. With increasing pressure, the 1200 µm channel - on the order of small arteries and veins - exhibited inertial cavitation, 1/2 subharmonics and 3/2 ultraharmonics, consistent with numerous previous reports. The 200 and 100 µm channels - in the size range of larger microvessels less affected by therapeutic focused ultrasound - exhibited a distinctly different behavior, having muted development of 1/2 subharmonics and 3/2 ultraharmonics and reduced persistence. These were associated with radiation forces displacing bubbles to the distal wall and inducing clusters that then rapidly dissipated along with emissions. As the diameter transitioned to 50 and then 15 µm - a size regime that is most relevant to therapeutic focused ultrasound - there was a higher threshold for the onset of inertial cavitation as well as subharmonics and ultraharmonics, which importantly had more complex orders that are not normally reported. Clusters also occurred in these channels (e.g. at 3 MPa, the mean lateral and axial sizes were 23 and 72 µm in the 15 µm channel; 50 and 90 µm in the 50 µm channel), however in this case they occupied the entire lumens and displaced the wall boundaries. Damage to the 15 µm channel was observed for both pulse types, but at a lower pressure for the long pulse. Experiments conducted with a 'nanobubble' (<0.45 µm) subpopulation of Definity followed broadly similar features to 'native' Definity, albeit at a higher pressure threshold for inertial cavitation. These results provide new insights into the behavior of microbubbles in small vessels at higher pressures and have implications for therapeutic focused ultrasound cavitation monitoring and control.
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Affiliation(s)
- Xiaoxiao Zhao
- Department of Medical Biophysics, University of Toronto, M5G 1L7, Canada; Sunnybrook Research Institute, 2075 Bayview Ave, Toronto M4N 3M5, Canada.
| | - Alex Wright
- Sunnybrook Research Institute, 2075 Bayview Ave, Toronto M4N 3M5, Canada
| | - David E Goertz
- Department of Medical Biophysics, University of Toronto, M5G 1L7, Canada; Sunnybrook Research Institute, 2075 Bayview Ave, Toronto M4N 3M5, Canada.
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Exner AA, Kolios MC. Bursting Microbubbles: How Nanobubble Contrast Agents Can Enable the Future of Medical Ultrasound Molecular Imaging and Image-Guided Therapy. Curr Opin Colloid Interface Sci 2021; 54:101463. [PMID: 34393610 PMCID: PMC8356903 DOI: 10.1016/j.cocis.2021.101463] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The field of medical ultrasound has undergone a significant evolution since the development of microbubbles as contrast agents. However, due to their size, microbubbles remain in the vasculature, and therefore have limited clinical applications. Building a better - and smaller - bubble can expand the applications of contrast-enhanced ultrasound by allowing bubbles to extravasate from blood vessels - creating new opportunities. In this review, we summarize recent research on the formulation and use of NBs as imaging agents and as therapeutic vehicles. We discuss the ongoing debates in the field and reluctance to accepting NBs as an acoustically active construct and a potentially impactful clinical tool that can help shape the future of medical ultrasound. We hope that the overview of key experimental and theoretical findings in the NB field presented in this paper provides a fundamental framework that will help clarify NB-ultrasound interactions and inspire engagement in the field.
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Affiliation(s)
- Agata A. Exner
- Departments of Radiology and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
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Pellow C, Cherin E, Abenojar EC, Exner AA, Zheng G, Demore CEM, Goertz DE. High-Frequency Array-Based Nanobubble Nonlinear Imaging in a Phantom and In Vivo. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:2059-2074. [PMID: 33513102 PMCID: PMC8296974 DOI: 10.1109/tuffc.2021.3055141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
There has been growing interest in nanobubbles (NBs) for vascular and extravascular ultrasound contrast imaging and therapeutic applications. Studies to date have generally utilized low frequencies (<12 MHz), high concentrations (>109 mL-1), and uncalibrated B-mode or contrast-mode on commercial systems without reporting investigations on NB signatures upon which the imaging protocols should be based. We recently demonstrated that low concentrations (106 mL-1) of porphyrin-lipid-encapsulated NBs scatter nonlinearly at low (2.5, 8 MHz) and high (12.5, 25, 30 MHz) frequencies in a pressure threshold-dependent manner that is advantageous for amplitude modulation (AM) imaging. Here, we implement pressure-calibrated AM at high frequency on a commercial preclinical array system to enhance sensitivity to nonlinear scattering of three phospholipid-based NB formulations. With this approach, improvements in contrast to tissue ratio relative to B-mode between 12.4 and 22.8 dB are demonstrated in a tissue-mimicking phantom, and between 6.7 and 14.8 dB in vivo.
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Chen H, Evangelou D, Loskutova K, Ghorbani M, Grishenkov D. On the Development of a Novel Contrast Pulse Sequence for Polymer-Shelled Microbubbles. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:1569-1579. [PMID: 33245694 DOI: 10.1109/tuffc.2020.3041206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Contrast agents are routinely used in ultrasound examinations. Nonlinear ultrasound imaging techniques have been developed over decades to enhance the contrast between the tissue and the blood pool after the injection of ultrasound contrast agents (UCAs). In this study, we introduce a new contrast pulse sequence, CPS4. The CPS4 combines pulse inversion (PI), subharmonic (SH), and ultraharmonic (UH) techniques to remove propagation distortion while capturing the unique SH and UH responses from UCAs. The novel CPS4 and conventional PI, SH, and UH techniques were used to detect the presence of a research-grade, thick-shell, polymer microbubble in a tissue-mimicking flow phantom. The contrast-to-tissue ratios (CTRs) obtained from the applications of all techniques were compared. The results show that the highest CTR of approximately 16 dB was obtained using CPS4, which was superior to the individual reference techniques: PI, SH, and UH techniques, in all scenarios considered in this study.
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Gupta I, Freid B, Masarapu V, Machado P, Trabulsi E, Wallace K, Halpern E, Forsberg F. Transrectal Subharmonic Ultrasound Imaging for Prostate Cancer Detection. Urology 2019; 138:106-112. [PMID: 31899231 DOI: 10.1016/j.urology.2019.12.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To assess the prostate cancer (CaP) detection rates of contrast-enhanced, transrectal subharmonic ultrasound imaging (SHI). MATERIALS AND METHODS This IRB-approved study enrolled 55 subjects. The initial 5 subjects were studied for SHI optimization, while the remaining 50 were evaluated with contrast-enhanced sonography using continuous SHI, color, and power Doppler as well as conventional grayscale, continuous color, and power Doppler and SHI combined with maximum flash replenishment. A maximum of 6 directed biopsy cores were obtained from sites of greatest asymmetrical enhancement, followed by spatially distributed cores in a double sextant distribution. Subharmonic time-intensity parameters, including time to peak intensity, peak intensity, and estimated perfusion were also evaluated for each directed biopsy core. Receiver operating characteristic curve analysis and conditional logistic regression were employed to assess the benefit of each modality and the quantitative SHI parameters. RESULTS Cancer was detected in 22 of 50 subjects. Among subjects with clinically significant CaP (n = 11), targeted cores were more likely to be positive (odds ratio 1.39, P = .02). The majority of patients detected by SHI demonstrated significant CaP (5/8); SHI remained an independent marker of malignancy in a multivariate logistic regression model (P = .027). Receiver operating characteristic curve analysis of imaging findings compared to biopsy results yielded diagnostic accuracies ranging from 0.59 to 0.80 for all imaging modalities with the highest being for quantitative subharmonic perfusion estimates. CONCLUSION This first-in-humans study provides a preliminary estimate of the diagnostic accuracy of SHI for detection of clinically significant CaP (up to 80%).
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Affiliation(s)
- I Gupta
- Thomas Jefferson University, Philadelphia, PA
| | - B Freid
- Thomas Jefferson University, Philadelphia, PA
| | - V Masarapu
- Thomas Jefferson University, Philadelphia, PA
| | - P Machado
- Thomas Jefferson University, Philadelphia, PA
| | - E Trabulsi
- Thomas Jefferson University, Philadelphia, PA
| | | | - E Halpern
- Thomas Jefferson University, Philadelphia, PA
| | - F Forsberg
- Thomas Jefferson University, Philadelphia, PA.
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Sojahrood AJ, Wegierak D, Haghi H, Karshfian R, Kolios MC. A simple method to analyze the super-harmonic and ultra-harmonic behavior of the acoustically excited bubble oscillator. ULTRASONICS SONOCHEMISTRY 2019; 54:99-109. [PMID: 30827907 DOI: 10.1016/j.ultsonch.2019.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/19/2019] [Accepted: 02/11/2019] [Indexed: 05/21/2023]
Abstract
The bubble oscillator is a highly nonlinear system, which makes it difficult to generate a comprehensive understanding of its oscillatory behavior. One method used to investigate such complex dynamical systems is the bifurcation analysis. Numerous investigations have employed the method of bifurcation diagrams to study the effect of different control parameters on the bubble behavior. These studies, however, focused mainly on investigating the subharmonic (SH) and chaotic oscillations of the bubbles. Super-harmonic (SuH) and ultra-harmonic (UH) bubble oscillations remain under-investigated. One reason is that the conventional method used for generating bifurcation diagrams cannot reliably identify features that are responsible for the identification of SuH and UH oscillations. Additionally, the conventional method cannot distinguish between the UHs and SHs. We introduce a simple procedure to address this shortcoming. In this method, the maxima of the bubble oscillatory response were selected and plotted alongside the traditional bifurcation points for the corresponding control parameter. Results show that depending on the control parameters the conventional method or the method of maxima may miss intricate details of the oscillations. In order to have a comprehensive knowledge on the rich dynamics of the system, the two methods should be employed side by side. Through plotting the two bifurcation structures in tandem, the oscillatory behavior of the bubble was analyzed with more detail, and stable SuH and UH bubble oscillations were investigated. Based on this new analysis, the conditions for the generation and amplification of UH and SuH regimes are discussed.
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Affiliation(s)
- A J Sojahrood
- Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada.
| | - D Wegierak
- Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada
| | - H Haghi
- Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada
| | - R Karshfian
- Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada
| | - Michael C Kolios
- Department of Physics, Ryerson University, Toronto, Canada; Institute for Biomedical Engineering, Science and Technology (IBEST) a partnership between Ryerson University and St. Mike's Hospital, Toronto, Ontario, Canada
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Arteaga-Marrero N, Mainou-Gomez JF, Brekke Rygh C, Lutay N, Roehrich D, Reed RK, Olsen DR. Radiation treatment monitoring with DCE-US in CWR22 prostate tumor xenografts. Acta Radiol 2019; 60:788-797. [PMID: 30231620 DOI: 10.1177/0284185118798167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Longitudinal monitoring of potential radiotherapy treatment effects can be determined by dynamic contrast-enhanced ultrasound (DCE-US). PURPOSE To assess functional parameters by means of DCE-US in a murine subcutaneous model of human prostate cancer, and their relationship to dose deposition and time-frame after treatment. A special focus has been placed to evaluate the vascular heterogeneity of the tumor and on the most suitable data analysis approach that reflects this heterogeneity. MATERIAL AND METHODS In vivo DCE-US was acquired 24 h and 48 h after radiation treatment with a single dose of 7.5 Gy and 10 Gy, respectively. Tumor vasculature was characterized pixelwise using the Brix pharmacokinetic analysis of the time-intensity curves. RESULTS Longitudinal changes were detected ( P < 0.001) at 24 h and 48 h after treatment. At 48 h, the eliminating rate constant of the contrast agent from the plasma, kel, was correlated ( P ≤ 0.05) positively with microvessel density (MVD; rτ = 0.7) and negatively with necrosis (rτ = -0.6) for the treated group. Furthermore, Akep, a parameter related to transcapillary transport properties, was also correlated to MVD (rτ = 0.6, P ≤ 0.05). CONCLUSION DCE-US has been shown to detect vascular changes at a very early stage after radiotherapy, which is a great advantage since DCE-US is non-invasive, available at most hospitals, and is low in cost compared to other techniques used in clinical practice.
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Affiliation(s)
- Natalia Arteaga-Marrero
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | | | - Cecilie Brekke Rygh
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Health Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Nataliya Lutay
- Imagene-iT AB, Medicon Village Scheelevägen 2, Lund, Sweden
| | - Dieter Roehrich
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Rolf K Reed
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Center for Cancer Biomarkers (CCBIO), University of Bergen, Bergen, Norway
| | - Dag R Olsen
- Department of Physics and Technology, University of Bergen, Bergen, Norway
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Shekhar H, Rowan JS, Doyley MM. Combining Subharmonic and Ultraharmonic Modes for Intravascular Ultrasound Imaging: A Preliminary Evaluation. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:2725-2732. [PMID: 28847499 PMCID: PMC5679122 DOI: 10.1016/j.ultrasmedbio.2017.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 07/13/2017] [Accepted: 07/15/2017] [Indexed: 05/12/2023]
Abstract
Contrast-enhanced intra-vascular ultrasound (CE-IVUS) imaging could provide clinicians a valuable tool to assess cardiovascular risk and guide the choice of therapeutic strategies. In this technical note, we evaluated the feasibility of combining subharmonic and ultraharmonic imaging to improve the performance of CE-IVUS. Vessel phantoms perfused with phospholipid-shelled ultrasound contrast agents were visualized using subharmonic, ultraharmonic and combined CE-IVUS modes with commercial peripheral and coronary imaging catheters. Flow channels as small as 0.8 mm and 0.5 mm were imaged at 12-MHz and 30-MHz transmit frequencies, respectively. Subharmonic and ultraharmonic imaging modes achieved a contrast-to-tissue ratio (CTR) up to 18.1 ± 1.8 dB and 19.6 ± 1.9 dB at 12-MHz, and 8.8 ± 1.8 and 12.5 ± 1.1 dB at 30-MHz transmit frequencies, respectively. Combining these modes improved the CTR to 32.5 ± 3.0 dB and 25.0 ± 1.6 dB at 12-MHz and 30-MHz transmit frequencies. These results underscore the potential of combined-mode CE-IVUS imaging. Furthermore, the demonstration of this approach with commercial catheters may serve as a first step toward the clinical translation of CE-IVUS.
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Affiliation(s)
- Himanshu Shekhar
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, USA.
| | - Jeffrey S Rowan
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, USA
| | - Marvin M Doyley
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, USA
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Daeichin V, van Rooij T, Skachkov I, Ergin B, Specht PAC, Lima A, Ince C, Bosch JG, van der Steen AFW, de Jong N, Kooiman K. Microbubble Composition and Preparation for High-Frequency Contrast-Enhanced Ultrasound Imaging: In Vitro and In Vivo Evaluation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:555-567. [PMID: 28113312 DOI: 10.1109/tuffc.2016.2640342] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Although high-frequency ultrasound imaging is gaining attention in various applications, hardly any ultrasound contrast agents (UCAs) dedicated to such frequencies (>15 MHz) are available for contrast-enhanced ultrasound (CEUS) imaging. Moreover, the composition of the limited commercially available UCAs for high-frequency CEUS (hfCEUS) is largely unknown, while shell properties have been shown to be an important factor for their performance. The aim of our study was to produce UCAs in-house for hfCEUS. Twelve different UCA formulations A-L were made by either sonication or mechanical agitation. The gas core consisted of C4F10 and the main coating lipid was either 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC; A-F formulation) or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC; G-L formulation). Mechanical agitation resulted in UCAs with smaller microbubbles (number weighted mean diameter ~1 [Formula: see text]) than sonication (number weighted mean diameter ~2 [Formula: see text]). UCA formulations with similar size distributions but different main lipid components showed that the DPPC-based UCA formulations had higher nonlinear responses at both the fundamental and subharmonic frequencies in vitro for hfCEUS using the Vevo2100 high-frequency preclinical scanner (FUJIFILM VisualSonics, Inc.). In addition, UCA formulations F (DSPC-based) and L (DPPC-based) that were made by mechanical agitation performed similar in vitro to the commercially available Target-Ready MicroMarker (FUJIFILM VisualSonics, Inc.). UCA formulation F also performed similar to Target-Ready MicroMarker in vivo in pigs with similar mean contrast intensity within the kidney ( n = 7 ), but formulation L did not. This is likely due to the lower stability of formulation L in vivo. Our study shows that DSPC-based microbubbles produced by mechanical agitation resulted in small microbubbles with high nonlinear responses suitable for hfCEUS imaging.
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Gupta I, Eisenbrey J, Stanczak M, Sridharan A, Dave JK, Liu JB, Hazard C, Wang X, Wang P, Li H, Wallace K, Forsberg F. Effect of Pulse Shaping on Subharmonic Aided Pressure Estimation In Vitro and In Vivo. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2017; 36:3-11. [PMID: 27943411 PMCID: PMC5191985 DOI: 10.7863/ultra.15.11106] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 04/15/2016] [Indexed: 05/10/2023]
Abstract
OBJECTIVES Subharmonic imaging (SHI) is a technique that uses the nonlinear oscillations of microbubbles when exposed to ultrasound at high pressures transmitting at the fundamental frequency ie, fo and receiving at half the transmit frequency (ie, fo /2). Subharmonic aided pressure estimation (SHAPE) is based on the inverse relationship between the subharmonic amplitude of the microbubbles and the ambient pressure change. METHODS Eight waveforms with different envelopes were optimized with respect to acoustic power at which the SHAPE study is most sensitive. The study was run with four input transmit cycles, first in vitro and then in vivo in three canines to select the waveform that achieved the best sensitivity for detecting changes in portal pressures using SHAPE. A Logiq 9 scanner with a 4C curvi-linear array was used to acquire 2.5 MHz radio-frequency data. Scanning was performed in dual imaging mode with B-mode imaging at 4 MHz and a SHI contrast mode transmitting at 2.5 MHz and receiving at 1.25 MHz. Sonazoid, which is a lipid stabilized gas filled bubble of perfluorobutane, was used as the contrast agent in this study. RESULTS A linear decrease in subharmonic amplitude with increased pressure was observed for all waveforms (r from -0.77 to -0.93; P < .001) in vitro. There was a significantly higher correlation of the SHAPE gradient with changing pressures for the broadband pulses as compared to the narrowband pulses in both in vitro and in vivo results. The highest correlation was achieved with a Gaussian windowed binomial filtered square wave with an r-value of -0.95. One of the three canines was eliminated for technical reasons, while the other two produced very similar results to those obtained in vitro (r from -0.72 to -0.98; P <.01). The most consistent in vivo results were achieved with the Gaussian windowed binomial filtered square wave (r = -0.95 and -0.96). CONCLUSIONS Using this waveform is an improvement to the existing SHAPE technique (where a square wave was used) and should make SHAPE more sensitive for noninvasively determining portal hypertension.
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Affiliation(s)
- Ipshita Gupta
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
- School of Biomedical Engineering, Sciences and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - John Eisenbrey
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Maria Stanczak
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Anush Sridharan
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
- Department of Electrical and Computer Engineering, Drexel University, Philadelphia, PA 19104, USA
| | - Jaydev K. Dave
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ji-Bin Liu
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | | | - Xinghua Wang
- Department of Ultrasound, The 2nd Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - Ping Wang
- Department of Ultrasound, The Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, China
| | - Huiwen Li
- Department of Ultrasound, Erdos Center Hospital, Erdos, Inner Mongolia 017000, China
| | | | - Flemming Forsberg
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Shekhar H, Huntzicker S, Awuor I, Doyley MM. Chirp-Coded Ultraharmonic Imaging with a Modified Clinical Intravascular Ultrasound System. ULTRASONIC IMAGING 2016; 38:403-419. [PMID: 26634777 DOI: 10.1177/0161734615618639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Imaging plaque microvasculature with contrast-enhanced intravascular ultrasound (IVUS) could help clinicians evaluate atherosclerosis and guide therapeutic interventions. In this study, we evaluated the performance of chirp-coded ultraharmonic imaging using a modified IVUS system (iLab™, Boston Scientific/Scimed) equipped with clinically available peripheral and coronary imaging catheters. Flow phantoms perfused with a phospholipid-encapsulated contrast agent were visualized using ultraharmonic imaging at 12 MHz and 30 MHz transmit frequencies. Flow channels with diameters as small as 0.8 mm and 0.5 mm were visualized using the peripheral and coronary imaging catheters. Radio-frequency signals were acquired at standard IVUS rotation speed, which resulted in a frame rate of 30 frames/s. Contrast-to-tissue ratios up to 17.9 ± 1.11 dB and 10.7 ± 2.85 dB were attained by chirp-coded ultraharmonic imaging at 12 MHz and 30 MHz transmit frequencies, respectively. These results demonstrate the feasibility of performing ultraharmonic imaging at standard frame rates with clinically available IVUS catheters using chirp-coded excitation.
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Affiliation(s)
- Himanshu Shekhar
- Department of Electrical and Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY, USA
| | - Steven Huntzicker
- Department of Electrical and Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY, USA
| | - Ivy Awuor
- Department of Electrical and Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY, USA
| | - Marvin M Doyley
- Department of Electrical and Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY, USA
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Daeichin V, Kooiman K, Skachkov I, Bosch JG, Theelen TL, Steiger K, Needles A, Janssen BJ, Daemen MJAP, van der Steen AFW, de Jong N, Sluimer JC. Quantification of Endothelial αvβ3 Expression with High-Frequency Ultrasound and Targeted Microbubbles: In Vitro and In Vivo Studies. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:2283-2293. [PMID: 27302657 DOI: 10.1016/j.ultrasmedbio.2016.05.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 06/06/2023]
Abstract
Angiogenesis is a critical feature of plaque development in atherosclerosis and might play a key role in both the initiation and later rupture of plaques. The precursory molecular or cellular pro-angiogenic events that initiate plaque growth and that ultimately contribute to plaque instability, however, cannot be detected directly with any current diagnostic modality. This study was designed to investigate the feasibility of ultrasound molecular imaging of endothelial αvβ3 expression in vitro and in vivo using αvβ3-targeted ultrasound contrast agents (UCAs). In the in vitro study, αvβ3 expression was confirmed by immunofluorescence in a murine endothelial cell line and detected using the targeted UCA and ultrasound imaging at 18-MHz transmit frequency. In the in vivo study, expression of endothelial αvβ3 integrin in murine carotid artery vessels and microvessels of the salivary gland was quantified using targeted UCA and high-frequency ultrasound in seven animals. Our results indicated that endothelial αvβ3 expression was significantly higher in the carotid arterial wall containing atherosclerotic lesions than in arterial segments without any lesions. We also found that the salivary gland can be used as an internal positive control for successful binding of targeted UCA to αvβ3 integrin. In conclusion, αvβ3-targeted UCA allows non-invasive assessment of the expression levels of αvβ3 on the vascular endothelium and may provide potential insights into early atherosclerotic plaque detection and treatment monitoring.
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Affiliation(s)
- Verya Daeichin
- Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands.
| | - Klazina Kooiman
- Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
| | - Ilya Skachkov
- Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
| | - Johan G Bosch
- Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
| | - Thomas L Theelen
- Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Katja Steiger
- Institute of Pathology, Technical University of Munich, Munich, Germany
| | | | - Ben J Janssen
- Department of Pharmacology, MUMC, Maastricht, The Netherlands
| | - Mat J A P Daemen
- Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands
| | - Antonius F W van der Steen
- Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands; Laboratory of Acoustical Wavefield Imaging, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands; Shenzhen Institute of Advanced Technologies, Shenzhen, China
| | - Nico de Jong
- Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands; Laboratory of Acoustical Wavefield Imaging, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands; Netherlands Heart Institute, Utrecht, The Netherlands
| | - Judith C Sluimer
- Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands
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Huntzicker S, Shekhar H, Doyley MM. Contrast-Enhanced Quantitative Intravascular Elastography: The Impact of Microvasculature on Model-Based Elastography. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:1167-81. [PMID: 26924697 PMCID: PMC4811726 DOI: 10.1016/j.ultrasmedbio.2015.12.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 12/18/2015] [Accepted: 12/22/2015] [Indexed: 05/03/2023]
Abstract
Model-based intravascular ultrasound elastography visualizes the stress distribution within vascular tissue-information that clinicians could use to predict the propensity of atherosclerotic plaque rupture. However, there are concerns that clusters of microvessels may reduce the accuracy of the estimated stress distribution. Consequently, we have developed a contrast-enhanced intravascular ultrasound system to investigate how plaque microvasculature affects the performance of model-based elastography. In simulations, diameters of 200, 400 and 800 μm were used, where the latter diameter represented a cluster of microvessels. In phantoms, we used a microvessel with a diameter of 750 μm. Peak stress errors of 3% and 38% were incurred in the fibrous cap when stress recovery was performed with and without a priori information about microvessel geometry. The results indicate that incorporating geometric information about plaque microvasculature obtained with contrast-enhanced ultrasound imaging improves the accuracy of estimates of the stress distribution within the fibrous cap precisely.
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Affiliation(s)
- Steven Huntzicker
- Department of Electrical & Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, New York, USA
| | - Himanshu Shekhar
- Department of Electrical & Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, New York, USA
| | - Marvin M Doyley
- Department of Electrical & Computer Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, New York, USA.
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15
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Lajoinie G, De Cock I, Coussios CC, Lentacker I, Le Gac S, Stride E, Versluis M. In vitro methods to study bubble-cell interactions: Fundamentals and therapeutic applications. BIOMICROFLUIDICS 2016; 10:011501. [PMID: 26865903 PMCID: PMC4733084 DOI: 10.1063/1.4940429] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/05/2016] [Indexed: 05/08/2023]
Abstract
Besides their use as contrast agents for ultrasound imaging, microbubbles are increasingly studied for a wide range of therapeutic applications. In particular, their ability to enhance the uptake of drugs through the permeabilization of tissues and cell membranes shows great promise. In order to fully understand the numerous paths by which bubbles can interact with cells and the even larger number of possible biological responses from the cells, thorough and extensive work is necessary. In this review, we consider the range of experimental techniques implemented in in vitro studies with the aim of elucidating these microbubble-cell interactions. First of all, the variety of cell types and cell models available are discussed, emphasizing the need for more and more complex models replicating in vivo conditions together with experimental challenges associated with this increased complexity. Second, the different types of stabilized microbubbles and more recently developed droplets and particles are presented, followed by their acoustic or optical excitation methods. Finally, the techniques exploited to study the microbubble-cell interactions are reviewed. These techniques operate over a wide range of timescales, or even off-line, revealing particular aspects or subsequent effects of these interactions. Therefore, knowledge obtained from several techniques must be combined to elucidate the underlying processes.
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Affiliation(s)
- Guillaume Lajoinie
- Physics of Fluids Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente , Enschede, The Netherlands
| | - Ine De Cock
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmaceutical Sciences, Ghent University , Ghent, Belgium
| | | | - Ine Lentacker
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Faculty of Pharmaceutical Sciences, Ghent University , Ghent, Belgium
| | - Séverine Le Gac
- MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente , Enschede, The Netherlands
| | - Eleanor Stride
- Institute of Biomedical Engineering, University of Oxford , Oxford, United Kingdom
| | - Michel Versluis
- Physics of Fluids Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente , Enschede, The Netherlands
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