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An J, Sugita N, Shinshi T. Microbubble detection on ultrasound imaging by utilizing phase patterned waves. Phys Med Biol 2024; 69:135003. [PMID: 38843808 DOI: 10.1088/1361-6560/ad5511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/06/2024] [Indexed: 06/21/2024]
Abstract
Objective.Super-resolution ultrasonography offers the advantage of visualization of intricate microvasculature, which is crucial for disease diagnosis. Mapping of microvessels is possible by localizing microbubbles (MBs) that act as contrast agents and tracking their location. However, there are limitations such as the low detectability of MBs and the utilization of a diluted concentration of MBs, leading to the extension of the acquisition time. We aim to enhance the detectability of MBs to reduce the acquisition time of acoustic data necessary for mapping the microvessels.Approach.We propose utilizing phase patterned waves (PPWs) characterized by spatially patterned phase distributions in the incident beam to achieve this. In contrast to conventional ultrasound irradiation methods, this irradiation method alters bubble interactions, enhancing the oscillation response of MBs and generating more significant scattered waves from specific MBs. This enhances the detectability of MBs, thereby enabling the detection of MBs that were undetectable by the conventional method. The objective is to maximize the overall detection of bubbles by utilizing ultrasound imaging with additional PPWs, including the conventional method. In this paper, we apply PPWs to ultrasound imaging simulations considering bubble-bubble interactions to elucidate the characteristics of PPWs and demonstrate their efficacy by employing PPWs on MBs fixed in a phantom by the experiment.Main results.By utilizing two types of PPWs in addition to the conventional ultrasound irradiation method, we confirmed the detection of up to 93.3% more MBs compared to those detected using the conventional method alone.Significance.Ultrasound imaging using additional PPWs made it possible to increase the number of detected MBs, which is expected to improve the efficiency of bubble detection.
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Affiliation(s)
- Junseok An
- Department of Mechanical Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Naohiro Sugita
- Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Tadahiko Shinshi
- Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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Deng L, Lea-Banks H, Jones RM, O’Reilly MA, Hynynen K. Three-dimensional super resolution ultrasound imaging with a multi-frequency hemispherical phased array. Med Phys 2023; 50:7478-7497. [PMID: 37702919 PMCID: PMC10872837 DOI: 10.1002/mp.16733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/27/2023] [Indexed: 09/14/2023] Open
Abstract
BACKGROUND High resolution imaging of the microvasculature plays an important role in both diagnostic and therapeutic applications in the brain. However, ultrasound pulse-echo sonography imaging the brain vasculatures has been limited to narrow acoustic windows and low frequencies due to the distortion of the skull bone, which sacrifices axial resolution since it is pulse length dependent. PURPOSE To overcome the detect limit, a large aperture 256-module sparse hemispherical transmit/receive array was used to visualize the acoustic emissions of ultrasound-vaporized lipid-coated decafluorobutane nanodroplets flowing through tube phantoms and within rabbit cerebral vasculature in vivo via passive acoustic mapping and super resolution techniques. METHODS Nanodroplets were vaporized with 55 kHz burst-mode ultrasound (burst length = 145 μs, burst repetition frequency = 9-45 Hz, peak negative acoustic pressure = 0.10-0.22 MPa), which propagates through overlying tissues well without suffering from severe distortions. The resulting emissions were received at a higher frequency (612 or 1224 kHz subarray) to improve the resulting spatial resolution during passive beamforming. Normal resolution three-dimensional images were formed using a delay, sum, and integrate beamforming algorithm, and super-resolved images were extracted via Gaussian fitting of the estimated point-spread-function to the normal resolution data. RESULTS With super resolution techniques, the mean lateral (axial) full-width-at-half-maximum image intensity was 16 ± 3 (32 ± 6) μm, and 7 ± 1 (15 ± 2) μm corresponding to ∼1/67 of the normal resolution at 612 and 1224 kHz, respectively. The mean positional uncertainties were ∼1/350 (lateral) and ∼1/180 (axial) of the receive wavelength in water. In addition, a temporal correlation between nanodroplet vaporization and the transmit waveform shape was observed, which may provide the opportunity to enhance the signal-to-noise ratio in future studies. CONCLUSIONS Here, we demonstrate the feasibility of vaporizing nanodroplets via low frequency ultrasound and simultaneously performing spatial mapping via passive beamforming at higher frequencies to improve the resulting spatial resolution of super resolution imaging techniques. This method may enable complete four-dimensional vascular mapping in organs where a hemispherical array could be positioned to surround the target, such as the brain, breast, or testicles.
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Affiliation(s)
- Lulu Deng
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, M4N 3M5, Canada
| | - Harriet Lea-Banks
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, M4N 3M5, Canada
| | - Ryan M. Jones
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, M4N 3M5, Canada
| | - Meaghan A. O’Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, M4N 3M5, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, M4N 3M5, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, M5S 3E2, Canada
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You Q, Lowerison MR, Shin Y, Chen X, Sekaran NVC, Dong Z, Llano DA, Anastasio MA, Song P. Contrast-Free Super-Resolution Power Doppler (CS-PD) Based on Deep Neural Networks. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1355-1368. [PMID: 37566494 PMCID: PMC10619974 DOI: 10.1109/tuffc.2023.3304527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2023]
Abstract
Super-resolution ultrasound microvessel imaging based on ultrasound localization microscopy (ULM) is an emerging imaging modality that is capable of resolving micrometer-scaled vessels deep into tissue. In practice, ULM is limited by the need for contrast injection, long data acquisition, and computationally expensive postprocessing times. In this study, we present a contrast-free super-resolution power Doppler (CS-PD) technique that uses deep networks to achieve super-resolution with short data acquisition. The training dataset is comprised of spatiotemporal ultrafast ultrasound signals acquired from in vivo mouse brains, while the testing dataset includes in vivo mouse brain, chicken embryo chorioallantoic membrane (CAM), and healthy human subjects. The in vivo mouse imaging studies demonstrate that CS-PD could achieve an approximate twofold improvement in spatial resolution when compared with conventional power Doppler. In addition, the microvascular images generated by CS-PD showed good agreement with the corresponding ULM images as indicated by a structural similarity index of 0.7837 and a peak signal-to-noise ratio (PSNR) of 25.52. Moreover, CS-PD was able to preserve the temporal profile of the blood flow (e.g., pulsatility) that is similar to conventional power Doppler. Finally, the generalizability of CS-PD was demonstrated on testing data of different tissues using different imaging settings. The fast inference time of the proposed deep neural network also allows CS-PD to be implemented for real-time imaging. These features of CS-PD offer a practical, fast, and robust microvascular imaging solution for many preclinical and clinical applications of Doppler ultrasound.
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Zhang G, Liao C, Hu JR, Hu HM, Lei YM, Harput S, Ye HR. Nanodroplet-Based Super-Resolution Ultrasound Localization Microscopy. ACS Sens 2023; 8:3294-3306. [PMID: 37607403 DOI: 10.1021/acssensors.3c00418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Over the past decade, super-resolution ultrasound localization microscopy (SR-ULM) has revolutionized ultrasound imaging with its capability to resolve the microvascular structures below the ultrasound diffraction limit. The introduction of this imaging technique enables the visualization, quantification, and characterization of tissue microvasculature. The early implementations of SR-ULM utilize microbubbles (MBs) that require a long image acquisition time due to the requirement of capturing sparsely isolated microbubble signals. The next-generation SR-ULM employs nanodroplets that have the potential to significantly reduce the image acquisition time without sacrificing the resolution. This review discusses various nanodroplet-based ultrasound localization microscopy techniques and their corresponding imaging mechanisms. A summary is given on the preclinical applications of SR-ULM with nanodroplets, and the challenges in the clinical translation of nanodroplet-based SR-ULM are presented while discussing the future perspectives. In conclusion, ultrasound localization microscopy is a promising microvasculature imaging technology that can provide new diagnostic and prognostic information for a wide range of pathologies, such as cancer, heart conditions, and autoimmune diseases, and enable personalized treatment monitoring at a microlevel.
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Affiliation(s)
- Ge Zhang
- Department of Medical Ultrasound, China Resources & Wisco General Hospital, Wuhan University of Science and Technology, Wuhan 430080, People's Republic of China
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan 430065, People's Republic of China
- Physics for Medicine Paris, Inserm U1273, ESPCI Paris, PSL University, CNRS, Paris 75015, France
| | - Chen Liao
- Department of Medical Ultrasound, China Resources & Wisco General Hospital, Wuhan University of Science and Technology, Wuhan 430080, People's Republic of China
- Medical College, Wuhan University of Science and Technology, Wuhan 430065, People's Republic of China
| | - Jun-Rui Hu
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China
| | - Hai-Man Hu
- Department of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan 430068, People's Republic of China
| | - Yu-Meng Lei
- Department of Medical Ultrasound, China Resources & Wisco General Hospital, Wuhan University of Science and Technology, Wuhan 430080, People's Republic of China
| | - Sevan Harput
- Department of Electrical and Electronic Engineering, London South Bank University, London SE1 0AA, U.K
| | - Hua-Rong Ye
- Department of Medical Ultrasound, China Resources & Wisco General Hospital, Wuhan University of Science and Technology, Wuhan 430080, People's Republic of China
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Hwang M, Zhang Z, Katz J, Freeman C, Kilbaugh T. Brain contrast-enhanced ultrasonography and elastography in infants. Ultrasonography 2022; 41:633-649. [PMID: 35879109 PMCID: PMC9532200 DOI: 10.14366/usg.21224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 03/20/2022] [Accepted: 03/30/2022] [Indexed: 11/19/2022] Open
Abstract
Advanced ultrasound techniques, including brain contrast-enhanced ultrasonography and elastography, are increasingly being explored to better understand infant brain health. While conventional brain ultrasonography provides a convenient, noninvasive means of assessing major intracranial pathologies, its value in revealing functional and physiologic insights into the brain lags behind advanced imaging techniques such as magnetic resonance imaging. In this regard, contrast-enhanced ultrasonography provides highly precise functional information on macrovascular and microvascular perfusion, while brain elastography offers information on brain stiffness that may be associated with relevant physiological factors of diagnostic, therapeutic, and/or prognostic utility. This review details the technical background, current understanding and utility, and future directions of these two emerging advanced ultrasound techniques for neonatal brain applications.
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Affiliation(s)
- Misun Hwang
- Department of Radiology, Children’s Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Zeng Zhang
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Joseph Katz
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Colbey Freeman
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Todd Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, Children’s Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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You Q, Trzasko JD, Lowerison MR, Chen X, Dong Z, ChandraSekaran NV, Llano DA, Chen S, Song P. Curvelet Transform-Based Sparsity Promoting Algorithm for Fast Ultrasound Localization Microscopy. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:2385-2398. [PMID: 35344488 PMCID: PMC9496596 DOI: 10.1109/tmi.2022.3162839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ultrasound localization microscopy (ULM) based on microbubble (MB) localization was recently introduced to overcome the resolution limit of conventional ultrasound. However, ULM is currently challenged by the requirement for long data acquisition times to accumulate adequate MB events to fully reconstruct vasculature. In this study, we present a curvelet transform-based sparsity promoting (CTSP) algorithm that improves ULM imaging speed by recovering missing MB localization signal from data with very short acquisition times. CTSP was first validated in a simulated microvessel model, followed by the chicken embryo chorioallantoic membrane (CAM), and finally, in the mouse brain. In the simulated microvessel study, CTSP robustly recovered the vessel model to achieve an 86.94% vessel filling percentage from a corrupted image with only 4.78% of the true vessel pixels. In the chicken embryo CAM study, CTSP effectively recovered the missing MB signal within the vasculature, leading to marked improvement in ULM imaging quality with a very short data acquisition. Taking the optical image as reference, the vessel filling percentage increased from 2.7% to 42.2% using 50ms of data acquisition after applying CTSP. CTSP used 80% less time to achieve the same 90% maximum saturation level as compared with conventional MB localization. We also applied CTSP on the microvessel flow speed maps and found that CTSP was able to use only 1.6s of microbubble data to recover flow speed images that have similar qualities as those constructed using 33.6s of data. In the mouse brain study, CTSP was able to reconstruct the majority of the cerebral vasculature using 1-2s of data acquisition. Additionally, CTSP only needed 3.2s of microbubble data to generate flow velocity maps that are comparable to those using 129.6s of data. These results suggest that CTSP can facilitate fast and robust ULM imaging especially under the circumstances of inadequate microbubble localizations.
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Le DQ, Papadopoulou V, Dayton PA. Effect of Acoustic Parameters and Microbubble Concentration on the Likelihood of Encapsulated Microbubble Coalescence. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2980-2989. [PMID: 34344561 PMCID: PMC8547186 DOI: 10.1016/j.ultrasmedbio.2021.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/23/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Microbubble contrast agents are commonly used for therapeutic and diagnostic imaging applications. Under certain conditions, these contrast agents can coalesce on ultrasound application and form larger bubbles than the initial population. The formation of large microbubbles potentially influences therapeutic outcomes and imaging quality. We studied clinically relevant ultrasound parameters related to low-pressure therapy and contrast-enhanced ultrasound imaging to determine their effect on microbubble coalescence and subsequent changes in microbubble size distributions in vitro. Results indicate that therapeutic ultrasound at low frequencies, moderate pressures and high duty cycles are capable of forming bubbles greater than two times larger than the initial bubble distribution. Furthermore, acoustic parameters related to contrast-enhanced ultrasound imaging that are at higher frequency, low-pressure and low-duty cycle exhibit no statistically significant changes in bubble diameter, suggesting that standard contrast ultrasound imaging does not cause coalescence. Overall, this work suggests that the microbubble coalescence phenomenon can readily occur at acoustic parameters used in therapeutic ultrasound, generating bubbles much larger than those found in commercial contrast agents, although coalescence is unlikely to be significant in diagnostic contrast-enhanced ultrasound imaging. This observation warrants further expansion of parameter ranges and investigation of resulting effects.
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Affiliation(s)
- David Q Le
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Virginie Papadopoulou
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
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From Anatomy to Functional and Molecular Biomarker Imaging and Therapy: Ultrasound Is Safe, Ultrafast, Portable, and Inexpensive. Invest Radiol 2021; 55:559-572. [PMID: 32776766 DOI: 10.1097/rli.0000000000000675] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ultrasound is the most widely used medical imaging modality worldwide. It is abundant, extremely safe, portable, and inexpensive. In this review, we consider some of the current development trends for ultrasound imaging, which build upon its current strength and the popularity it experiences among medical imaging professional users.Ultrasound has rapidly expanded beyond traditional radiology departments and cardiology practices. Computing power and data processing capabilities of commonly available electronics put ultrasound systems in a lab coat pocket or on a user's mobile phone. Taking advantage of new contributions and discoveries in ultrasound physics, signal processing algorithms, and electronics, the performance of ultrasound systems and transducers have progressed in terms of them becoming smaller, with higher imaging performance, and having lower cost. Ultrasound operates in real time, now at ultrafast speeds; kilohertz frame rates are already achieved by many systems.Ultrasound has progressed beyond anatomical imaging and monitoring blood flow in large vessels. With clinical approval of ultrasound contrast agents (gas-filled microbubbles) that are administered in the bloodstream, tissue perfusion studies are now routine. Through the use of modern ultrasound pulse sequences, individual microbubbles, with subpicogram mass, can be detected and observed in real time, many centimeters deep in the body. Ultrasound imaging has broken the wavelength barrier; by tracking positions of microbubbles within the vasculature, superresolution imaging has been made possible. Ultrasound can now trace the smallest vessels and capillaries, and obtain blood velocity data in those vessels.Molecular ultrasound imaging has now moved closer to clinic; the use of microbubbles with a specific affinity to endothelial biomarkers allows selective accumulation and retention of ultrasound contrast in the areas of ischemic injury, inflammation, or neoangiogenesis. This will aid in noninvasive molecular imaging and may provide additional help with real-time guidance of biopsy, surgery, and ablation procedures.The ultrasound field can be tightly focused inside the body, many centimeters deep, with millimeter precision, and ablate lesions by energy deposition, with thermal or mechanical bioeffects. Some of such treatments are already in clinical use, with more indications progressing through the clinical trial stage. In conjunction with intravascular microbubbles, focused ultrasound can be used for tissue-specific drug delivery; localized triggered release of sequestered drugs from particles in the bloodstream may take time to get to clinic. A combination of intravascular microbubbles with circulating drug and low-power ultrasound allows transient opening of vascular endothelial barriers, including blood-brain barrier; this approach has reached clinical trial stage. Therefore, the drugs that normally would not be getting to the target tissue in the brain will now have an opportunity to produce therapeutic efficacy.Overall, medical ultrasound is developing at a brisk rate, even in an environment where other imaging modalities are also advancing rapidly and may be considered more lucrative. With all the current advances that we discuss, and many more to come, ultrasound may help solve many problems that modern medicine is facing.
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Tan Y, Chen M, Chen H, Wu J, Liu J. Enhanced Ultrasound Contrast of Renal-Clearable Luminescent Gold Nanoparticles. Angew Chem Int Ed Engl 2021; 60:11713-11717. [PMID: 33665956 DOI: 10.1002/anie.202017273] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/14/2021] [Indexed: 12/31/2022]
Abstract
Renal-clearable nanoparticles are typically fast eliminated through the free glomerular filtration, which show weak interaction with the renal compartments and negligible ultrasound signals, raising challenges in direct imaging of kidney diseases. Here, we report the ultrasmall renal-clearable luminescent gold nanoparticles (AuNPs) with both pH-induced charge reversal and aggregation properties, and discover that enhanced ultrasound contrast could be facilely acquired through the increased tubular reabsorption and in situ aggregation of AuNPs in renal tubule cells in injured kidneys. The tuning elimination pathway of the renal-clearable luminescent AuNPs is further demonstrated to provide a synergistical fluorescence and ultrasound imaging strategy for diagnosing early kidney injury with precise anatomical information.
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Affiliation(s)
- Yue Tan
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Miaona Chen
- Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Huarui Chen
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Juefei Wu
- Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Jinbin Liu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China
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Tan Y, Chen M, Chen H, Wu J, Liu J. Enhanced Ultrasound Contrast of Renal‐Clearable Luminescent Gold Nanoparticles. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202017273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Yue Tan
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 China
| | - Miaona Chen
- Department of Cardiology Nanfang Hospital Southern Medical University Guangzhou 510515 China
| | - Huarui Chen
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 China
| | - Juefei Wu
- Department of Cardiology Nanfang Hospital Southern Medical University Guangzhou 510515 China
| | - Jinbin Liu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 China
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Huang C, Zhang W, Gong P, Lok UW, Tang S, Yin T, Zhang X, Zhu L, Sang M, Song P, Zheng R, Chen S. Super-resolution ultrasound localization microscopy based on a high frame-rate clinical ultrasound scanner: an in-human feasibility study. Phys Med Biol 2021; 66. [PMID: 33725687 DOI: 10.1088/1361-6560/abef45] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/16/2021] [Indexed: 12/11/2022]
Abstract
Non-invasive detection of microvascular alterations in deep tissuesin vivoprovides critical information for clinical diagnosis and evaluation of a broad-spectrum of pathologies. Recently, the emergence of super-resolution ultrasound localization microscopy (ULM) offers new possibilities for clinical imaging of microvasculature at capillary level. Currently, the clinical utility of ULM on clinical ultrasound scanners is hindered by the technical limitations, such as long data acquisition time, high microbubble (MB) concentration, and compromised tracking performance associated with low imaging frame-rate. Here we present a robust in-human ULM on a high frame-rate (HFR) clinical ultrasound scanner to achieve super-resolution microvessel imaging using a short acquisition time (<10 s). Ultrasound MB data were acquired from different human tissues, including a healthy liver and a diseased liver with acute-on-chronic liver failure, a kidney, a pancreatic tumor, and a breast mass using an HFR clinical scanner. By leveraging the HFR and advanced processing techniques including sub-pixel motion registration, MB signal separation, and Kalman filter-based tracking, MBs can be robustly localized and tracked for ULM under the circumstances of relatively high MB concentration associated with standard clinical MB administration and limited data acquisition time in humans. Subtle morphological and hemodynamic information in microvasculature were shown based on data acquired with single breath-hold and free-hand scanning. Compared with contrast-enhanced power Doppler generated based on the same MB dataset, ULM showed a 5.7-fold resolution improvement in a vessel based on a linear transducer, and provided a wide-range blood flow speed measurement that is Doppler angle-independent. Microvasculatures with complex hemodynamics can be well-differentiated at super-resolution in both normal and pathological tissues. This preliminary study implemented the ultrafast in-human ULM in various human tissues based on a clinical scanner that supports HFR imaging, indicating the potentials of the technique for various clinical applications. However, rigorous validation of the technique in imaging human microvasculature (especially for those tiny vessel structure), preferably with a gold standard, is still required.
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Affiliation(s)
- Chengwu Huang
- Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, United States of America
| | - Wei Zhang
- Department of Ultrasound, Guangdong Key Laboratory of Liver Disease Research, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China
| | - Ping Gong
- Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, United States of America
| | - U-Wai Lok
- Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, United States of America
| | - Shanshan Tang
- Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, United States of America
| | - Tinghui Yin
- Department of Ultrasound, Guangdong Key Laboratory of Liver Disease Research, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China
| | - Xirui Zhang
- Shenzhen Mindray Bio-Medical Electronics Co. Ltd, Shenzhen, Guangdong, People's Republic of China
| | - Lei Zhu
- Shenzhen Mindray Bio-Medical Electronics Co. Ltd, Shenzhen, Guangdong, People's Republic of China
| | - Maodong Sang
- Shenzhen Mindray Bio-Medical Electronics Co. Ltd, Shenzhen, Guangdong, People's Republic of China
| | - Pengfei Song
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Rongqin Zheng
- Department of Ultrasound, Guangdong Key Laboratory of Liver Disease Research, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China
| | - Shigao Chen
- Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, United States of America
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Chen Q, Song H, Yu J, Kim K. Current Development and Applications of Super-Resolution Ultrasound Imaging. SENSORS 2021; 21:s21072417. [PMID: 33915779 PMCID: PMC8038018 DOI: 10.3390/s21072417] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 02/07/2023]
Abstract
Abnormal changes of the microvasculature are reported to be key evidence of the development of several critical diseases, including cancer, progressive kidney disease, and atherosclerotic plaque. Super-resolution ultrasound imaging is an emerging technology that can identify the microvasculature noninvasively, with unprecedented spatial resolution beyond the acoustic diffraction limit. Therefore, it is a promising approach for diagnosing and monitoring the development of diseases. In this review, we introduce current super-resolution ultrasound imaging approaches and their preclinical applications on different animals and disease models. Future directions and challenges to overcome for clinical translations are also discussed.
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Affiliation(s)
- Qiyang Chen
- Department of Bioengineering, School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA;
- Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Hyeju Song
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Korea;
| | - Jaesok Yu
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Korea;
- DGIST Robotics Research Center, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Korea
- Correspondence: (J.Y.); (K.K.)
| | - Kang Kim
- Department of Bioengineering, School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA;
- Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA
- Department of Mechanical Engineering and Materials Science, School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Correspondence: (J.Y.); (K.K.)
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Helbert A, Gaud E, Segers T, Botteron C, Frinking P, Jeannot V. Monodisperse versus Polydisperse Ultrasound Contrast Agents: In Vivo Sensitivity and safety in Rat and Pig. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:3339-3352. [PMID: 33008649 DOI: 10.1016/j.ultrasmedbio.2020.07.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 05/21/2023]
Abstract
Recent advances in the field of monodisperse microbubble synthesis by flow focusing allow for the production of foam-free, highly concentrated and monodisperse lipid-coated microbubble suspensions. It has been found that in vitro, such monodisperse ultrasound contrast agents (UCAs) improve the sensitivity of contrast-enhanced ultrasound imaging. Here, we present the first in vivo study in the left ventricle of rat and pig with this new monodisperse bubble agent. We systematically characterize the acoustic sensitivity and safety of the agent at an imaging frequency of 2.5 MHz as compared with three commercial polydisperse UCAs (SonoVue/Lumason, Definity/Luminity and Optison) and one research-grade polydisperse agent with the same shell composition as the monodisperse bubbles. The monodisperse microbubbles, which had a diameter of 4.2 μm, crossed the pulmonary vasculature, and their echo signal could be measured at least as long as that of the polydisperse UCAs, indicating that microfluidically formed monodisperse microbubbles are stable in vivo. Furthermore, it was found that the sensitivity of the monodisperse agent, expressed as the mean echo power per injected bubble, was at least 10 times higher than that of the polydisperse UCAs. Finally, the safety profile of the monodisperse microbubble suspension was evaluated by injecting 400 and 2000 times the imaging dose, and neither physiologic nor pathologic changes were found, which is a first indication that monodisperse lipid-coated microbubbles formed by flow focusing are safe for in vivo use. The more uniform acoustic response and corresponding increased imaging sensitivity of the monodisperse agent may boost emerging applications of microbubbles and ultrasound such as molecular imaging and therapy.
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Affiliation(s)
- Alexandre Helbert
- Bracco Suisse S.A., Route de la Galaise 31, 1228 Plan-les-Ouates, Switzerland
| | - Emmanuel Gaud
- Bracco Suisse S.A., Route de la Galaise 31, 1228 Plan-les-Ouates, Switzerland
| | - Tim Segers
- Physics of Fluids Group, MESA + Institute for Nanotechnology, Technical Medical (TechMed) Center, University of Twente, Enschede, The Netherlands; Former employee of Bracco Suisse S.A
| | | | | | - Victor Jeannot
- Bracco Suisse S.A., Route de la Galaise 31, 1228 Plan-les-Ouates, Switzerland.
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14
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Wildeboer RR, Sammali F, van Sloun RJG, Huang Y, Chen P, Bruce M, Rabotti C, Shulepov S, Salomon G, Schoot BC, Wijkstra H, Mischi M. Blind Source Separation for Clutter and Noise Suppression in Ultrasound Imaging: Review for Different Applications. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:1497-1512. [PMID: 32091998 DOI: 10.1109/tuffc.2020.2975483] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Blind source separation (BSS) refers to a number of signal processing techniques that decompose a signal into several "source" signals. In recent years, BSS is increasingly employed for the suppression of clutter and noise in ultrasonic imaging. In particular, its ability to separate sources based on measures of independence rather than their temporal or spatial frequency content makes BSS a powerful filtering tool for data in which the desired and undesired signals overlap in the spectral domain. The purpose of this work was to review the existing BSS methods and their potential in ultrasound imaging. Furthermore, we tested and compared the effectiveness of these techniques in the field of contrast-ultrasound super-resolution, contrast quantification, and speckle tracking. For all applications, this was done in silico, in vitro, and in vivo. We found that the critical step in BSS filtering is the identification of components containing the desired signal and highlighted the value of a priori domain knowledge to define effective criteria for signal component selection.
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15
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Stride E, Segers T, Lajoinie G, Cherkaoui S, Bettinger T, Versluis M, Borden M. Microbubble Agents: New Directions. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:1326-1343. [PMID: 32169397 DOI: 10.1016/j.ultrasmedbio.2020.01.027] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/09/2020] [Accepted: 01/26/2020] [Indexed: 05/24/2023]
Abstract
Microbubble ultrasound contrast agents have now been in use for several decades and their safety and efficacy in a wide range of diagnostic applications have been well established. Recent progress in imaging technology is facilitating exciting developments in techniques such as molecular, 3-D and super resolution imaging and new agents are now being developed to meet their specific requirements. In parallel, there have been significant advances in the therapeutic applications of microbubbles, with recent clinical trials demonstrating drug delivery across the blood-brain barrier and into solid tumours. New agents are similarly being tailored toward these applications, including nanoscale microbubble precursors offering superior circulation times and tissue penetration. The development of novel agents does, however, present several challenges, particularly regarding the regulatory framework. This article reviews the developments in agents for diagnostic, therapeutic and "theranostic" applications; novel manufacturing techniques; and the opportunities and challenges for their commercial and clinical translation.
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Affiliation(s)
- Eleanor Stride
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK.
| | - Tim Segers
- Physics of Fluids Group, Technical Medical (TechMed) Centre, MESA+ Institute for Nanotechnology, University of Twente, The Netherlands
| | - Guillaume Lajoinie
- Physics of Fluids Group, Technical Medical (TechMed) Centre, MESA+ Institute for Nanotechnology, University of Twente, The Netherlands
| | - Samir Cherkaoui
- Bracco Suisse SA - Business Unit Imaging, Global R&D, Plan-les-Ouates, Switzerland
| | - Thierry Bettinger
- Bracco Suisse SA - Business Unit Imaging, Global R&D, Plan-les-Ouates, Switzerland
| | - Michel Versluis
- Physics of Fluids Group, Technical Medical (TechMed) Centre, MESA+ Institute for Nanotechnology, University of Twente, The Netherlands
| | - Mark Borden
- Mechanical Engineering Department, University of Colorado, Boulder, CO, USA
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16
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Fischer C, Krix M, Weber MA, Loizides A, Gruber H, Jung EM, Klauser A, Radzina M, Dietrich CF. Contrast-Enhanced Ultrasound for Musculoskeletal Applications: A World Federation for Ultrasound in Medicine and Biology Position Paper. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:1279-1295. [PMID: 32139152 DOI: 10.1016/j.ultrasmedbio.2020.01.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 06/10/2023]
Abstract
This World Federation for Ultrasound in Medicine and Biology position paper reviews the diagnostic potential of ultrasound contrast agents for clinical decision-making and provides general advice for optimal contrast-enhanced ultrasound performance in musculoskeletal issues. In this domain, contrast-enhanced ultrasound performance has increasingly been investigated with promising results, but still lacks everyday clinical application and standardized techniques; therefore, experts summarized current knowledge according to published evidence and best personal experience. The goal was to intensify and standardize the use and administration of ultrasound contrast agents to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.
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Affiliation(s)
- Christian Fischer
- Center for Orthopaedics, Trauma Surgery and Spinal Cord Injury, Ultrasound Center, HTRG-Heidelberg Trauma Research Group, Heidelberg University Hospital, Heidelberg, Germany.
| | | | - Marc-André Weber
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Center Rostock, Rostock, Germany
| | - Alexander Loizides
- Department of Radiology, Ultrasound Center, Innsbruck Medical University, Innsbruck, Austria
| | - Hannes Gruber
- Department of Radiology, Ultrasound Center, Innsbruck Medical University, Innsbruck, Austria
| | | | - Andrea Klauser
- Department of Radiology, Ultrasound Center, Innsbruck Medical University, Innsbruck, Austria
| | - Maija Radzina
- Diagnostic Radiology Institute, Riga Stradins University, Riga, Latvia
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17
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Christensen-Jeffries K, Couture O, Dayton PA, Eldar YC, Hynynen K, Kiessling F, O'Reilly M, Pinton GF, Schmitz G, Tang MX, Tanter M, van Sloun RJG. Super-resolution Ultrasound Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:865-891. [PMID: 31973952 PMCID: PMC8388823 DOI: 10.1016/j.ultrasmedbio.2019.11.013] [Citation(s) in RCA: 163] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 11/17/2019] [Accepted: 11/20/2019] [Indexed: 05/02/2023]
Abstract
The majority of exchanges of oxygen and nutrients are performed around vessels smaller than 100 μm, allowing cells to thrive everywhere in the body. Pathologies such as cancer, diabetes and arteriosclerosis can profoundly alter the microvasculature. Unfortunately, medical imaging modalities only provide indirect observation at this scale. Inspired by optical microscopy, ultrasound localization microscopy has bypassed the classic compromise between penetration and resolution in ultrasonic imaging. By localization of individual injected microbubbles and tracking of their displacement with a subwavelength resolution, vascular and velocity maps can be produced at the scale of the micrometer. Super-resolution ultrasound has also been performed through signal fluctuations with the same type of contrast agents, or through switching on and off nano-sized phase-change contrast agents. These techniques are now being applied pre-clinically and clinically for imaging of the microvasculature of the brain, kidney, skin, tumors and lymph nodes.
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Affiliation(s)
- Kirsten Christensen-Jeffries
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, London, United Kingdom
| | - Olivier Couture
- Institute of Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS FRE 2031, PSL University, Paris, France.
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Yonina C Eldar
- Department of Mathematics and Computer Science, Weizmann Institute of Science, Rehovot, Israel
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Meaghan O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Gianmarco F Pinton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Georg Schmitz
- Chair for Medical Engineering, Faculty for Electrical Engineering and Information Technology, Ruhr University Bochum, Bochum, Germany
| | - Meng-Xing Tang
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Mickael Tanter
- Institute of Physics for Medicine Paris, Inserm U1273, ESPCI Paris, CNRS FRE 2031, PSL University, Paris, France
| | - Ruud J G van Sloun
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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18
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Soulioti DE, Espindola D, Dayton PA, Pinton GF. Super-Resolution Imaging Through the Human Skull. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:25-36. [PMID: 31494546 DOI: 10.1109/tuffc.2019.2937733] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
High-resolution transcranial ultrasound imaging in humans has been a persistent challenge for ultrasound due to the imaging degradation effects from aberration and reverberation. These mechanisms depend strongly on skull morphology and have high variability across individuals. Here, we demonstrate the feasibility of human transcranial super-resolution imaging using a geometrical focusing approach to efficiently concentrate energy at the region of interest, and a phase correction focusing approach that takes the skull morphology into account. It is shown that using the proposed focused super-resolution method, we can image a 208- [Formula: see text] microtube behind a human skull phantom in both an out-of-plane and an in-plane configuration. Individual phase correction profiles for the temporal region of the human skull were calculated and subsequently applied to transmit-receive a custom focused super-resolution imaging sequence through a human skull phantom, targeting the 208- [Formula: see text] diameter microtube at 68.5 mm in depth and at 2.5 MHz. Microbubble contrast agents were diluted to a concentration of 1.6×106 bubbles/mL and perfused through the microtube. It is shown that by correcting for the skull aberration, the RF signal amplitude from the tube improved by a factor of 1.6 in the out-of-plane focused emission case. The lateral registration error of the tube's position, which in the uncorrected case was 990 [Formula: see text], was reduced to as low as 50 [Formula: see text] in the corrected case as measured in the B-mode images. Sensitivity in microbubble detection for the phase-corrected case increased by a factor of 1.48 in the out-of-plane imaging case, while, in the in-plane target case, it improved by a factor of 1.31 while achieving an axial registration correction from an initial 1885- [Formula: see text] error for the uncorrected emission, to a 284- [Formula: see text] error for the corrected counterpart. These findings suggest that super-resolution imaging may be used far more generally as a clinical imaging modality in the brain.
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19
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Newsome IG, Kierski TM, Dayton PA. Assessment of the Superharmonic Response of Microbubble Contrast Agents for Acoustic Angiography as a Function of Microbubble Parameters. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:2515-2524. [PMID: 31174922 PMCID: PMC7202402 DOI: 10.1016/j.ultrasmedbio.2019.04.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 05/07/2023]
Abstract
Acoustic angiography is a superharmonic contrast-enhanced ultrasound imaging technique that enables 3-D high-resolution microvascular visualization. This technique utilizes a dual-frequency imaging strategy, transmitting at a low frequency and receiving at a higher frequency, to detect high-frequency contrast agent signatures and separate them from tissue background. Prior studies have illustrated differences in microbubble scatter dependent on microbubble size and composition; however, most previously reported data have utilized a relatively narrow frequency bandwidth centered around the excitation frequency. To date, a comprehensive study of isolated microbubble superharmonic responses with a broadband dual-frequency system has not been performed. Here, the superharmonic signal production of 14 contrast agents with various gas cores, shell compositions, and bubble diameters at mechanical indices of 0.2 to 1.2 was evaluated using a transmit 4 MHz, receive 25 MHz configuration. Results indicate that perfluorocarbon cores or lipid shells with 18- or 20-carbon acyl chains produce more superharmonic signal than sulfur hexafluoride cores or lipid shells with 16-carbon acyl chains, respectively. As microbubble diameter increases from 1 to 4 µm, superharmonic generation decreases. In a comparison of two clinical agents, Definity and Optison, and one preclinical agent, Micromarker, Optison produced the least superharmonic signal. Overall, this work suggests that microbubbles around 1 μm in diameter with perfluorocarbon cores and longer-chained lipid shells perform best for superharmonic imaging at 4 MHz. Studies have found that microbubble superharmonic response follows trends different from those described in prior studies using a narrower frequency bandwidth centered around the excitation frequency. Future work will apply these results in vivo to optimize the sensitivity of acoustic angiography.
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Affiliation(s)
- Isabel G Newsome
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Thomas M Kierski
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
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20
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Chen Z, Pulsipher KW, Chattaraj R, Hammer DA, Sehgal CM, Lee D. Engineering the Echogenic Properties of Microfluidic Microbubbles Using Mixtures of Recombinant Protein and Amphiphilic Copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10079-10086. [PMID: 30768278 PMCID: PMC6698903 DOI: 10.1021/acs.langmuir.8b03882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Microbubbles are used as ultrasound contrast agents in medical diagnosis and also have shown great promise in ultrasound-mediated therapy. However, short lifetime and broad size distribution of microbubbles limit their applications in therapy and imaging. Moreover, it is challenging to tailor the echogenic response of microbubbles to make them suitable for specific applications. To overcome these challenges, we use microfluidic flow-focusing to prepare monodisperse microbubbles with a mixture of a recombinant amphiphilic protein, oleosin, and a synthetic amphiphilic copolymer, Pluronic. We show that these microbubbles have superior uniformity and stability under ultrasonic stimulation compared to commercial agents. We also demonstrate that by using different Pluronics, the echogenic response of the microbubbles can be tailored. Our work shows the versatility of using the combination of microfluidics and protein/copolymer mixtures as a method of engineering microbubbles. This tunability could potentially be important and powerful in producing microbubble agents for theranostic applications.
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Affiliation(s)
- Zhuo Chen
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Katherine W. Pulsipher
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Rajarshi Chattaraj
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, United States
| | - Daniel A. Hammer
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Chandra M. Sehgal
- Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, United States
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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21
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Mohanty K, Papadopoulou V, Newsome IG, Shelton S, Dayton PA, Muller M. Ultrasound multiple scattering with microbubbles can differentiate between tumor and healthy tissue in vivo. Phys Med Biol 2019; 64:115022. [PMID: 30995615 PMCID: PMC6876296 DOI: 10.1088/1361-6560/ab1a44] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most solid tumors are characterized by highly dense, isotropic vessel networks. Characterization of such features has shown promise for early cancer diagnosis. Ultrasound diffusion has been used to characterize the micro-architecture of complex media, such as bone and the lungs. In this work, we examine a non-invasive diffusion-based ultrasound technique to assess neo-vascularization. Because the diffusion constant reflects the density of scatterers in heterogeneous media, we hypothesize that by injecting microbubbles into the vasculature, ultrasound diffusivity can reflect vascular density (VD), thus differentiating the microvascular patterns between tumors and healthy tissue. The diffusion constant and its anisotropy are shown to be significantly different between fibrosarcoma tumors (n = 16) and control tissue (n = 18) in a rat animal model in vivo. The diffusion constant values for control and tumor were found to be 1.38 ± 0.51 mm2 µs-1 and 0.65 ± 0.27 mm2 µs-1, respectively. These results are corroborated with VD from acoustic angiography (AA) data, confirming increased vessel density in tumors compared to controls. The diffusion constant offers a promising way to quantitatively assess vascular networks when combined with contrast agents, which may allow early tumor detection and characterization.
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Affiliation(s)
- Kaustav Mohanty
- Department of Mechanical and Aerospace Engineering, NC State University, Raleigh, NC 27695, United States of America
| | - Virginie Papadopoulou
- UNC—NCSU Joint Department of Biomedical Engineering, UNC Chapel Hill, Chapel Hill, NC 27599, United States of America
| | - Isabel G Newsome
- UNC—NCSU Joint Department of Biomedical Engineering, UNC Chapel Hill, Chapel Hill, NC 27599, United States of America
| | - Sarah Shelton
- UNC—NCSU Joint Department of Biomedical Engineering, UNC Chapel Hill, Chapel Hill, NC 27599, United States of America
| | - Paul A Dayton
- UNC—NCSU Joint Department of Biomedical Engineering, UNC Chapel Hill, Chapel Hill, NC 27599, United States of America
| | - Marie Muller
- Department of Mechanical and Aerospace Engineering, NC State University, Raleigh, NC 27695, United States of America
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22
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Brown J, Christensen-Jeffries K, Harput S, Zhang G, Zhu J, Dunsby C, Tang MX, Eckersley RJ. Investigation of Microbubble Detection Methods for Super-Resolution Imaging of Microvasculature. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2019; 66:676-691. [PMID: 30676955 DOI: 10.1109/tuffc.2019.2894755] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ultrasound super-resolution techniques use the response of microbubble (MB) contrast agents to visualize the microvasculature. Techniques that localize isolated bubble signals first require detection algorithms to separate the MB and tissue responses. This work explores the three main MB detection techniques for super-resolution of microvasculature. Pulse inversion (PI), differential imaging (DI), and singular value decomposition (SVD) filtering were compared in terms of the localization accuracy, precision, and contrast-to-tissue ratio. MB responses were simulated based on the properties of Sonovue and using the Marmottant model. Nonlinear propagation through tissue was modeled using the k-Wave software package. For the parameters studied, the results show that PI is most appropriate for low frequency applications, but also most dependent on transducer bandwidth. SVD is preferable for high frequency acquisition where localization precision on the order of a few microns is possible. PI is largely independent of flow direction and speed compared to SVD and DI, so is appropriate for visualizing the slowest flows and tortuous vasculature. SVD is unsuitable for stationary MBs and can introduce a localization error on the order of hundreds of microns over the speed range 0-2 mm/s and flow directions from lateral (parallel to probe) to axial (perpendicular to probe). DI is only suitable for flow rates >0.5 mm/s or as flow becomes more axial. Overall, this study develops an MB and tissue nonlinear simulation platform to improve understanding of how different MB detection techniques can impact the super-resolution process and explores some of the factors influencing the suitability of each.
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23
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Song P, Manduca A, Trzasko JD, Daigle RE, Chen S. On the Effects of Spatial Sampling Quantization in Super-Resolution Ultrasound Microvessel Imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:2264-2276. [PMID: 29993999 PMCID: PMC6215740 DOI: 10.1109/tuffc.2018.2832600] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Ultrasound super-resolution (SR) microvessel imaging technologies are rapidly emerging and evolving. The unprecedented combination of imaging resolution and penetration promises a wide range of preclinical and clinical applications. This paper concerns spatial quantization error in SR imaging, a common issue that involves a majority of current SR imaging methods. While quantization error can be alleviated by the microbubble localization process (e.g., via upsampling or parametric fitting), it is unclear to what extent the localization process can suppress the spatial quantization error induced by discrete sampling. It is also unclear when low spatial sampling frequency will result in irreversible quantization errors that cannot be suppressed by the localization process. This paper had two goals: 1) to systematically investigate the effect of quantization in SR imaging and establish principles of adequate SR imaging spatial sampling that yield minimal quantization error with proper localization methods and 2) to compare the performance of various localization methods and study the level of tolerance of each method to quantization. We conducted experiments on a small wire target and on a microbubble flow phantom. We found that the Fourier analysis of an oversampled spatial profile of the microbubble signal could provide reliable guidance for selecting beamforming spatial sampling frequency. Among various localization methods, parametric Gaussian fitting and centroid-based localization on upsampled data had better microbubble localization performance and were less susceptible to quantization error than peak intensity-based localization methods. When spatial sampling resolution was low, parametric Gaussian fitting-based localization had the best performance in suppressing quantization error, and could produce acceptable SR microvessel imaging with no significant quantization artifacts. The findings from this paper can be used in practice to help intelligently determine the minimum requirement of spatial sampling for robust microbubble localization to avoid adding or even reduce the burden of computational cost and data storage that are commonly associated with SR imaging.
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Affiliation(s)
- Pengfei Song
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA
| | - Joshua D. Trzasko
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA
| | | | - Shigao Chen
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA
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24
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Espindola D, Lin F, Soulioti DE, Dayton PA, Pinton GF. Adaptive Multifocus Beamforming for Contrast-Enhanced-Super-Resolution Ultrasound Imaging in Deep Tissue. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:2255-2263. [PMID: 30136938 DOI: 10.1109/tuffc.2018.2865903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Contrast-enhanced-super-resolution ultrasound imaging, also referred to as ultrasound localization microscopy, can resolve vessels that are smaller than the diffraction limit and has recently been able to generate super-resolved vascular images of shallow in vivo structures in small animals. To fully translate this technology to the clinic, it is advantageous to be able to detect microbubbles at deeper locations in tissue while maintaining a short acquisition time. Current implementations of this imaging method rely on plane-wave imaging. This method has the advantage of maximizing the frame rate, which is important due to the large amount of frames required for super-resolution processing. However, the wide planar beam used to illuminate the field of view produces poor contrast and low sensitivity bubble detection. Here, we propose an "adaptive multifocus" sequence, a new ultrasound imaging sequence that combines the high frame rate feature of a plane wave with the increased bubble detection sensitivity of a focused beam. This sequence simultaneously sonicates two or more foci with a single emission, hence retaining a high frame rate, yet achieving improved sensitivity to microbubbles. In the limit of one target, the beam reduces to a conventional focused transmission; and for an infinite number of targets, it converges to plane-wave imaging. Numerical simulations, using the full-wave code, are performed to compare the point spread function of the proposed sequence to that generated by the plane-wave emission. Our numerical results predict an improvement of up to 15 dB in the signal-to-noise ratio. Ex vivo experiments of a tissue-embedded microtube phantom are used to generate super-resolved images and to compare the adaptive beamforming approach to plane-wave imaging. These experimental results show that the adaptive multifocus sequence successfully detects 744 microbubble events at 60 mm when they are undetectable by the plane-wave sequence under the same imaging conditions. At a shallower depth of 44 mm, the proposed adaptive multifocus method detects 6.9 times more bubbles than plane-wave imaging (1763 versus 257 bubble events).
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25
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Yoon H, Hallam KA, Yoon C, Emelianov SY. Super-Resolution Imaging With Ultrafast Ultrasound Imaging of Optically Triggered Perfluorohexane Nanodroplets. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:2277-2285. [PMID: 29993686 PMCID: PMC6325306 DOI: 10.1109/tuffc.2018.2829740] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Super-resolution imaging with moving microbubbles has shown potential in identifying fine details of deep-lying vascular compartments. To image the extravascular targets, this paper has employed nanometer-sized, optically triggered perfluorohexane nanodroplets (PFHnDs). In response to pulsed laser irradiation, the PFHnDs repeatedly vaporize and stochastically recondense, resulting in random changes of ultrasound signals. Our previous study has shown that the stochastic recondensation of the PFHnDs can be used to isolate individual PFHnDs for super-resolution imaging. This paper introduces an improved method for super-resolution imaging with ultrafast ultrasound imaging of PFHnDs. The previous method was based on subtraction of two consecutive ultrasound images to detect signals from recondensed, isolated droplets, whereas our current method compounds respective multiple pre- and post-recondensation ultrafast ultrasound images prior to subtraction to improve the spatial resolution further. To evaluate the axial and lateral resolutions of our method, we repeatedly imaged a phantom containing PFHnDs using a programmable ultrasound system synchronized with a pulsed laser system. As a result, our method improved the lateral and axial resolutions by 54% and 68%, respectively, over the previous super-resolution imaging approach, indicating that it can be used for localizing extravascular molecular targets with superior accuracy.
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Affiliation(s)
- Heechul Yoon
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332 USA ()
| | - Kristina A. Hallam
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA 30332 USA
| | - Changhan Yoon
- Department of Biomedical Engineering, Inje University, Gimhae, Gyeongsangnam-do 50834 Republic of Korea
| | - Stanislav Y. Emelianov
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332 USA, and with Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA 30332 USA ()
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26
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Couture O, Hingot V, Heiles B, Muleki-Seya P, Tanter M. Ultrasound Localization Microscopy and Super-Resolution: A State of the Art. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:1304-1320. [PMID: 29994673 DOI: 10.1109/tuffc.2018.2850811] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Because it drives the compromise between resolution and penetration, the diffraction limit has long represented an unreachable summit to conquer in ultrasound imaging. Within a few years after the introduction of optical localization microscopy, we proposed its acoustic alter ego that exploits the micrometric localization of microbubble contrast agents to reconstruct the finest vessels in the body in-depth. Various groups now working on the subject are optimizing the localization precision, microbubble separation, acquisition time, tracking, and velocimetry to improve the capacity of ultrasound localization microscopy (ULM) to detect and distinguish vessels much smaller than the wavelength. It has since been used in vivo in the brain, the kidney, and tumors. In the clinic, ULM is bound to improve drastically our vision of the microvasculature, which could revolutionize the diagnosis of cancer, arteriosclerosis, stroke, and diabetes.
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27
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Li Y, Chen Y, Du M, Chen ZY. Ultrasound Technology for Molecular Imaging: From Contrast Agents to Multimodal Imaging. ACS Biomater Sci Eng 2018; 4:2716-2728. [PMID: 33434997 DOI: 10.1021/acsbiomaterials.8b00421] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Ultrasound (US) takes advantage of ultrasound contrast agents (UCAs) to further increase the sensitivity and specificity of monitoring at the cellular level, which has had a considerable effect on the modern molecular imaging field. Gas-filled microbubbles (MBs) as UCAs in the bloodstream generate resonant volumetric oscillations in response to rapid variations in acoustic pressure, which are related to both the acoustic parameters of applied ultrasound and the physicochemical properties of the contrast agents. Nanoscale UCAs have been developed and have attracted much attention due to their utility in detecting extravascular lesions. Ultrasound molecular assessment is achieved by binding disease-specific ligands to the surface of UCAs, which have been designed to target tissue biomarkers in the area of interest, such as blood vessels, inflammation, or thrombosis. Additionally, the development of multimodal imaging technology is conducive for integration of the advantages of various imaging techniques to acquire additional diagnostic information. In this review paper, the present status and the critical issues for developing ultrasound contrast agents and multimodal imaging applications are described. Conventional MB UCAs are first introduced, including their research material, diagnostic applications, and intrinsic limitations. Then, recent progress in developing targeted UCAs and phase-inversion contrast agents for diagnostic purposes is discussed. Finally, we review the present status and the critical issues for developing ultrasound-based multimodal imaging applications and summarize the existing challenges and future prospects.
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Affiliation(s)
- Yue Li
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, People's Republic of China
| | - Yuhao Chen
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, People's Republic of China
| | - Meng Du
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, People's Republic of China
| | - Zhi-Yi Chen
- Department of Ultrasound Medicine, Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, People's Republic of China
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28
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A High-Efficiency Super-Resolution Reconstruction Method for Ultrasound Microvascular Imaging. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8071143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The emergence of super-resolution imaging makes it possible to display the microvasculatures clearly using ultrasound imaging, which is of great importance in the early diagnosis of cancer. At present, the super-resolution performance can only be achieved when the sampling signal is long enough (usually more than 10,000 frames). Thus, the imaging time resolution is not suitable for clinical use. In this paper, we proposed a novel super-resolution reconstruction method, which is proved to have a satisfactory resolution using shorter sampling signal sequences. In the microbubble localization step, the integrated form of the 2D Gaussian function is innovatively adopted for image deconvolution in our method, which enhances the accuracy of microbubble positioning. In the trajectory tracking step, for the first time the averaged shifted histogram technique is presented for the visualization, which greatly improves the precision of reconstruction. In vivo experiments on rabbits were conducted to verify the effectiveness of the proposed method. Compared to the conventional reconstruction method, our method significantly reduces the Full-Width-at-Half-Maximum (FWHM) by 50% using only 400-frame signals. Besides, there is no significant increase in the running time using the proposed method. Considering its imaging performance and used frame number, the conclusion can be drawn that the proposed method advances the application of super-resolution imaging to the clinical use with a much higher time resolution.
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