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Sugerman GP, Bechtel GN, Malinowska Z, Parekh SH, Rausch MK. Mechanical properties of clot made from human and bovine whole blood differ significantly. J Mech Behav Biomed Mater 2024; 154:106508. [PMID: 38513312 DOI: 10.1016/j.jmbbm.2024.106508] [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: 08/18/2023] [Revised: 02/24/2024] [Accepted: 03/13/2024] [Indexed: 03/23/2024]
Abstract
Thromboembolism - that is, clot formation and the subsequent fragmentation of clot - is a leading cause of death worldwide. Clots' mechanical properties are critical determinants of both the embolization process and the pathophysiological consequences thereof. Thus, understanding and quantifying the mechanical properties of clots is important to our ability to treat and prevent thromboembolic disease. However, assessing these properties from in vivo clots is experimentally challenging. Therefore, we and others have turned to studying in vitro clot mimics instead. Unfortunately, there are significant discrepancies in the reported properties of these clot mimics, which have been hypothesized to arise from differences in experimental techniques and blood sources. The goal of our current work is therefore to compare the mechanical behavior of clots made from the two most common sources, human and bovine blood, using the same experimental techniques. To this end, we tested clots under pure shear with and without initial cracks, under cyclic loading, and under stress relaxation. Based on these data, we computed and compared stiffness, strength, work-to-rupture, fracture toughness, relaxation time constants, and prestrain. While clots from both sources behaved qualitatively similarly, they differed quantitatively in almost every metric. We also correlated each mechanical metric to measures of blood composition. Thereby, we traced this inter-species variability in clot mechanics back to significant differences in hematocrit, but not platelet count. Thus, our work suggests that the results of past studies that have used bovine blood to make in vitro mimics - without adjusting blood composition - should be interpreted carefully. Future studies about the mechanical properties of blood clots should focus on human blood alone.
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Affiliation(s)
- Gabriella P Sugerman
- University of Texas at Austin, Department of Biomedical Engineering, 107 W Dean Keeton St, Austin, TX 78712, United States of America
| | - Grace N Bechtel
- University of Texas at Austin, Department of Biomedical Engineering, 107 W Dean Keeton St, Austin, TX 78712, United States of America
| | - Zuzanna Malinowska
- University of Texas at Austin, Department of Aerospace Engineering & Engineering Mechanics, 2617 Wichita St, Austin, TX 78712, United States of America
| | - Sapun H Parekh
- University of Texas at Austin, Department of Biomedical Engineering, 107 W Dean Keeton St, Austin, TX 78712, United States of America
| | - Manuel K Rausch
- University of Texas at Austin, Department of Biomedical Engineering, 107 W Dean Keeton St, Austin, TX 78712, United States of America; University of Texas at Austin, Department of Aerospace Engineering & Engineering Mechanics, 2617 Wichita St, Austin, TX 78712, United States of America; University of Texas at Austin, Department of Mechanical Engineering, 204 E Dean Keeton St, Austin, TX 78712, United States of America; University of Texas at Austin, Oden Institute for Computational Engineering and Sciences, 201 E 24th St, Austin, TX 78712, United States of America.
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Chen X, Li X, Turco S, van Sloun RJG, Mischi M. Ultrasound Viscoelastography by Acoustic Radiation Force: A State-of-the-Art Review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2024; 71:536-557. [PMID: 38526897 DOI: 10.1109/tuffc.2024.3381529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Ultrasound elastography (USE) is a promising tool for tissue characterization as several diseases result in alterations of tissue structure and composition, which manifest as changes in tissue mechanical properties. By imaging the tissue response to an applied mechanical excitation, USE mimics the manual palpation performed by clinicians to sense the tissue elasticity for diagnostic purposes. Next to elasticity, viscosity has recently been investigated as an additional, relevant, diagnostic biomarker. Moreover, since biological tissues are inherently viscoelastic, accounting for viscosity in the tissue characterization process enhances the accuracy of the elasticity estimation. Recently, methods exploiting different acquisition and processing techniques have been proposed to perform ultrasound viscoelastography. After introducing the physics describing viscoelasticity, a comprehensive overview of the currently available USE acquisition techniques is provided, followed by a structured review of the existing viscoelasticity estimators classified according to the employed processing technique. These estimators are further reviewed from a clinical usage perspective, and current outstanding challenges are discussed.
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Bosio G, Destrempes F, Roy Cardinal MH, Cloutier G. Effect of rt-PA on Shear Wave Mechanical Assessment and Quantitative Ultrasound Properties of Blood Clot Kinetics In Vitro. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2024; 43:829-840. [PMID: 38205972 DOI: 10.1002/jum.16411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024]
Abstract
OBJECTIVE The consequences associated with blood clots are numerous and are responsible for many deaths worldwide. The assessment of treatment efficacy is necessary for patient follow-up and to detect treatment-resistant patients. The aim of this study was to characterize the effect of treatment on blood clots in vitro using quantitative ultrasound parameters. METHODS Blood from 10 pigs was collected to form three clots per pig in gelatin phantoms. Clots were subjected to 1) no treatment, 2) rt-PA (recombinant tissue plasminogen activator) treatment after 20 minutes of clotting, and 3) rt-PA treatment after 60 minutes of clotting. Clots were weighted before and after the experiment to assess the treatment effect by the mass loss. The clot kinetics was studied over 100 minutes using elastography (Young's modulus, shear wave dispersion, and shear wave attenuation). Homodyne K-distribution (HKD) parameters derived from speckle statistics were also studied during clot formation and dissolving (diffuse-to-total signal power ratio and intensity parameters). RESULTS Treated clots loosed significantly more mass than non-treated ones (P < .005). A significant increase in Young's modulus was observed over time (P < .001), and significant reductions were seen for treated clots at 20 or 60 minutes compared with untreated ones (P < .001). The shear wave dispersion differed for treated clots at 60 minutes versus no treatments (P < .001). The shear wave attenuation decreased over time (P < .001), and was different for clots treated at 20 minutes versus no treatments (P < .031). The HKD intensity parameter varied over time (P < .032), and was lower for clots treated at 20 and 60 minutes than those untreated (P < .001 and P < .02). CONCLUSION The effect of rt-PA treatment could be confirmed by a decrease in Young's modulus and HKD intensity parameter. The shear wave dispersion and shear wave attenuation were sensitive to late and early treatments, respectively. The Young's modulus, shear wave attenuation, and HKD intensity parameter varied over time despite treatment.
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Affiliation(s)
- Guillaume Bosio
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
- Institute of Biomedical Engineering, University of Montreal, Montreal, Quebec, Canada
| | - François Destrempes
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
| | - Marie-Hélène Roy Cardinal
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
| | - Guy Cloutier
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
- Institute of Biomedical Engineering, University of Montreal, Montreal, Quebec, Canada
- Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Montreal, Quebec, Canada
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Bosio G, Destrempes F, Yazdani L, Roy Cardinal MH, Cloutier G. Resonance, Velocity, Dispersion, and Attenuation of Ultrasound-Induced Shear Wave Propagation in Blood Clot In Vitro Models. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2024; 43:535-551. [PMID: 38108551 DOI: 10.1002/jum.16387] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/24/2023] [Accepted: 11/25/2023] [Indexed: 12/19/2023]
Abstract
OBJECTIVE Improve the characterization of mechanical properties of blood clots. Parameters derived from shear wave (SW) velocity and SW amplitude spectra were determined for gel phantoms and in vitro blood clots. METHODS Homogeneous phantoms and phantoms with gel or blood clot inclusions of different diameters and mechanical properties were analyzed. SW amplitude spectra were used to observe resonant peaks. Parameters derived from those resonant peaks were related to mimicked blood clot properties. Three regions of interest were tested to analyze where resonances occurred the most. For blood experiments, 20 samples from different pigs were analyzed over time during a 110-minute coagulation period using the Young modulus, SW frequency dispersion, and SW attenuation. RESULTS The mechanical resonance was manifested by an increase in the number of SW spectral peaks as the inclusion diameter was reduced (P < .001). In blood clot inclusions, the Young modulus increased over time during coagulation (P < .001). Descriptive spectral parameters (frequency peak, bandwidth, and distance between resonant peaks) were linearly correlated with clot elasticity values (P < .001) with R2 = .77 for the frequency peak, .60 for the bandwidth, and .48 for the distance between peaks. The SW dispersion and SW attenuation reflecting the viscous behavior of blood clots decreased over time (P < .001), mainly in the early stage of coagulation (first minutes). CONCLUSION The confined soft inclusion configuration favored SW mechanical resonances potentially challenging the computation of spectral-based parameters, such as the SW attenuation. The impact of resonances can be reduced by properly selecting the region of interest for data analysis.
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Affiliation(s)
- Guillaume Bosio
- Institute of Biomedical Engineering, University of Montreal, Montreal, Quebec, Canada
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
| | - François Destrempes
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
| | - Ladan Yazdani
- Institute of Biomedical Engineering, University of Montreal, Montreal, Quebec, Canada
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
| | - Marie-Hélène Roy Cardinal
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
| | - Guy Cloutier
- Institute of Biomedical Engineering, University of Montreal, Montreal, Quebec, Canada
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, Quebec, Canada
- Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Montreal, Quebec, Canada
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Biswas D, Heo J, Sang P, Dey P, Han K, Ko JH, Won SM, Son D, Suh M, Kim HS, Ok JG, Park HJ, Baac HW. Micro-ultrasonic Assessment of Early Stage Clot Formation and Whole Blood Coagulation Using an All-Optical Ultrasound Transducer and Adaptive Signal Processing Algorithm. ACS Sens 2022; 7:2940-2950. [PMID: 36107765 DOI: 10.1021/acssensors.2c00875] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Abnormal formation of solid thrombus inside a blood vessel can cause thrombotic morbidity and mortality. This necessitates early stage diagnosis, which requires quantitative assessment with a small volume, for effective therapy with low risk to unwanted development of various diseases. We propose a micro-ultrasonic diagnosis using an all-optical ultrasound-based spectral sensing (AOUSS) technique for sensitive and quantitative characterization of early stage and whole blood coagulation. The AOUSS technique detects and analyzes minute viscoelastic variations of blood at a micro-ultrasonic spot (<100 μm) defined by laser-generated focused ultrasound (LGFU). This utilizes (1) a uniquely designed optical transducer configuration for frequency-spectral matching and wideband operation (6 dB widths: 7-32 MHz and d.c. ∼ 46 MHz, respectively) and (2) an empirical mode decomposition (EMD)-based signal process particularly adapted to nonstationary LGFU signals backscattered from the spot. An EMD-derived spectral analysis enables one to assess viscoelastic variations during the initiation of fibrin formation, which occurs at a very early stage of blood coagulation (1 min) with high sensitivity (frequency transition per storage modulus increment = 8.81 MHz/MPa). Our results exhibit strong agreement with those obtained by conventional rheometry (Pearson's R > 0.95), which are also confirmed by optical microscopy. The micro-ultrasonic and high-sensitivity detection of AOUSS poses a potential clinical significance, serving as a screening modality to diagnose early stage clot formation (e.g., as an indicator for hypercoagulation of blood) and stages of blood-to-clot transition to check a potential risk for development into thrombotic diseases.
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Affiliation(s)
- Deblina Biswas
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.,School of Bioengineering and Food Technology, Shoolini University, Solan, Himachal Pradesh 173229, India
| | - Jeongmin Heo
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Pilgyu Sang
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Prasanta Dey
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kayoung Han
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Department of Biomedical Engineering, Department of Intelligent Precision Healthcare Convergence (IPHC), Biomedical Institute of Convergence (BICS), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jong Hwan Ko
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sang Min Won
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Donghee Son
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Minah Suh
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Department of Biomedical Engineering, Department of Intelligent Precision Healthcare Convergence (IPHC), Biomedical Institute of Convergence (BICS), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyung Sik Kim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jong G Ok
- Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea
| | - Hui Joon Park
- Department of Organic and Nano Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Hyoung Won Baac
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
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An Intermodal Correlation Study among Imaging, Histology, Procedural and Clinical Parameters in Cerebral Thrombi Retrieved from Anterior Circulation Ischemic Stroke Patients. J Clin Med 2022; 11:jcm11195976. [PMID: 36233842 PMCID: PMC9572771 DOI: 10.3390/jcm11195976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/30/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
The precise characterization of cerebral thrombi prior to an interventional procedure can ease the procedure and increase its success. This study investigates how well cerebral thrombi can be characterized by computed tomography (CT), magnetic resonance (MR) and histology, and how parameters obtained by these methods correlate with each other as well as with the interventional procedure and clinical parameters. Cerebral thrombi of 25 patients diagnosed by CT with acute ischemic stroke were acquired by mechanical thrombectomy and, subsequently, scanned by a high spatial-resolution 3D MRI including T1-weighted imaging, apparent diffusion coefficient (ADC), T2 mapping and then finally analyzed by histology. Parameter pairs with Pearson correlation coefficient more than 0.5 were further considered by explaining a possible cause for the correlation and its impact on the difficulty of the interventional procedure and the treatment outcome. Significant correlations were found between the variability of ADC and the duration of the mechanical recanalization, the deviation in average Hounsfield units (HU) and the number of passes with the thrombectomy device, length of the thrombus, its RBC content and many others. This study also demonstrates the clinical potentials of high spatial resolution multiparametric MRI in characterization of thrombi and its use for interventional procedure planning.
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Bosio G, Zenati N, Destrempes F, Chayer B, Pernod G, Cloutier G. Shear Wave Elastography and Quantitative Ultrasound as Biomarkers to Characterize Deep Vein Thrombosis In Vivo. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2022; 41:1807-1816. [PMID: 34713918 DOI: 10.1002/jum.15863] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/02/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
OBJECTIVE Investigate shear wave elastography (SWE) and quantitative ultrasound (QUS) parameters in patients hospitalized for lower limb deep vein thrombosis (DVT). METHOD Sixteen patients with DVT were recruited and underwent SWE and radiofrequency data acquisitions for QUS on day 0, day 7, and day 30 after the beginning of symptoms, in both proximal and distal zones of the clot identified on B-mode scan. SWE and QUS features were computed to differentiate between thrombi at day 0, day 7, and day 30 following treatment with heparin or oral anticoagulant. The Young's modulus from SWE was computed, as well as QUS homodyned K-distribution (HKD) parameters reflecting blood clot structure. Median and interquartile range of SWE and QUS parameters within clot were taken as features. RESULTS In the proximal zone of the clot, the HKD ratio of coherent-to-diffuse backscatter median showed a significant decrease from day 7 to day 30 (P = .036), while the HKD ratio of diffuse-to-total backscatter median presented a significant increase from day 7 to day 30 (P = .0491). In the distal zone of the clot, the HKD normalized intensity of the echo envelope median showed a significant increase from day 0 to day 30 (P = .0062). No SWE features showed statistically significant differences over time. Nonetheless, a trend of lower median of Young's modulus within clot for patients who developed a pulmonary embolism was observed. CONCLUSION QUS features may be relevant to characterize clot's evolution over time. Further analysis of their clinical interpretation and validation on a larger dataset would deserve to be studied.
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Affiliation(s)
- Guillaume Bosio
- Institute of Biomedical Engineering, University of Montreal, Montréal, Québec, Canada
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada
| | - Nora Zenati
- UGA UFRM-Université Grenoble Alpes-UFR Médecine, Grenoble, France
| | - François Destrempes
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada
| | - Boris Chayer
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada
| | - Gilles Pernod
- UGA UFRM-Université Grenoble Alpes-UFR Médecine, Grenoble, France
- Centre Hospitalier Universitaire de Grenoble, Grenoble, France
- F-CRIN INNOVTE Network, Saint Etienne, France
| | - Guy Cloutier
- Institute of Biomedical Engineering, University of Montreal, Montréal, Québec, Canada
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada
- Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Montréal, Québec, Canada
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Costa-Júnior JFS, Parcero GC, Machado JC. Shear Elastic Coefficient of Normal and Fibrinogen-Deficient Clotting Plasma Obtained with a Sphere-Motion-Based Acoustic-Radiation-Force Approach. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:111-123. [PMID: 34674885 DOI: 10.1016/j.ultrasmedbio.2021.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
Blood coagulation is a process involving several chemical reactions governed by coagulation factors, during which the shear elastic coefficient, μ, varies as the medium transitions from liquid to gel phase. This work used ultrasound to measure μ during the clotting of human plasma samples by tracking the motion of a glass sphere located inside a cuvette filled with the plasma. A 2.03 MHz ultrasonic system generated an impulsive acoustic radiation force acting on the sphere, and a 4.89 MHz pulse-echo ultrasonic system tracked the sphere displacement induced by that force. Measurements of μ were determined by fitting a μ-dependent theoretical model to the motion waveform of the sphere immersed in clotting normal plasma and plasma samples with fibrinogen (FI) concentrations of 1.2 (FI-deficiency) and 3.6 (FI-normal) g/L. For normal plasma, μ started at 14.22 Pa and increased rapidly until 2 min, then slowly until it reached 210.23 Pa at 35 min after the clotting process started. A similar trend was exhibited in plasma samples with FI concentrations of 1.2 and 3.6 g/L, with μ reaching 120.55 and 679.42 Pa, respectively. A theoretical model, related to the kinetics of clot-structure formation, describes the time changes of μ for the clotting plasma samples. The sphere-motion-based acoustic-radiation-force approach allowed us to measure the shear elastic coefficient during the coagulation process of plasma samples with normal and deficient FI concentrations. Our results suggest that the method used in this study is capable of being used to detect bleeding disorders.
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Affiliation(s)
- José Francisco Silva Costa-Júnior
- Brazilian Air Force Academy, Pirassununga, Brazil; Biomedical Engineering Program-COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | | | - João Carlos Machado
- Biomedical Engineering Program-COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Post-Graduation Program on Surgical Sciences, School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Preclinical modeling of mechanical thrombectomy. J Biomech 2021; 130:110894. [PMID: 34915309 DOI: 10.1016/j.jbiomech.2021.110894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/21/2022]
Abstract
Mechanical thrombectomy to treat large vessel occlusions (LVO) causing a stroke is one of the most effective treatments in medicine, with a number needed to treat to improve clinical outcomes as low as 2.6. As the name implies, it is a mechanical solution to a blocked artery and modeling these mechanics preclinically for device design, regulatory clearance and high-fidelity physician training made clinical applications possible. In vitro simulation of LVO is extensively used to characterize device performance in representative vascular anatomies with physiologically accurate hemodynamics. Embolus analogues, validated against clots extracted from patients, provide a realistic simulated use experience. In vitro experimentation produces quantitative results such as particle analysis of distal emboli generated during the procedure, as well as pressure and flow throughout the experiment. Animal modeling, used mostly for regulatory review, allows estimation of device safety. Other than one recent development, nearly all animal modeling does not incorporate the desired target organ, the brain, but rather is performed in the extracranial circulation. Computational modeling of the procedure remains at the earliest stages but represents an enormous opportunity to rapidly characterize and iterate new thrombectomy concepts as well as optimize procedure workflow. No preclinical model is a perfect surrogate; however, models available can answer important questions during device development and have to date been successful in delivering efficacious and safe devices producing excellent clinical outcomes. This review reflects on the developments of preclinical modeling of mechanical thrombectomy with particular focus on clinical translation, as well as articulate existing gaps requiring additional research.
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Auboire L, Fouan D, Grégoire JM, Ossant F, Plag C, Escoffre JM, Bouakaz A. Acoustic and Elastic Properties of a Blood Clot during Microbubble-Enhanced Sonothrombolysis: Hardening of the Clot with Inertial Cavitation. Pharmaceutics 2021; 13:pharmaceutics13101566. [PMID: 34683859 PMCID: PMC8537785 DOI: 10.3390/pharmaceutics13101566] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 11/16/2022] Open
Abstract
Stroke is the second leading cause of death worldwide. Existing therapies present limitations, and other therapeutic alternatives are sought, such as sonothrombolysis with microbubbles (STL). The aim of this study was to evaluate the change induced by STL with or without recombinant tissue-type plasminogen activator (rtPA) on the acoustic and elastic properties of the blood clot by measuring its sound speed (SoS) and shear wave speed (SWS) with high frequency ultrasound and ultrafast imaging, respectively. An in-vitro setup was used and human blood clots were submitted to a combination of microbubbles and rtPA. The results demonstrate that STL induces a raise of SoS in the blood clot, specifically when combined with rtPA (p < 0.05). Moreover, the combination of rtPA and STL induces a hardening of the clot in comparison to rtPA alone (p < 0.05). This is the first assessment of acoustoelastic properties of blood clots during STL. The combination of rtPA and STL induce SoS and hardening of the clot, which is known to impair the penetration of thrombolytic drugs and their efficacy.
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Costa-Júnior JFS, Machado JC. Dynamic assessment of plasma clotting in samples with distinct fibrinogen concentrations using impulsive acoustic radiation force. ULTRASONICS 2021; 116:106515. [PMID: 34252874 DOI: 10.1016/j.ultras.2021.106515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 06/12/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
While some diseases reduce fibrinogen concentration, others increase the amount of this clotting factor in the blood. Some studies have shown that the fibrinogen concentration in the blood is related to the stiffness of the formed clot. Hence, the aim of this study was to employ an ultrasonic method based on impulsive acoustic radiation force (IARF) to identify the fibrinogen concentration (coagulation factor I) in a plasma sample by means of peak-displacement (PD), time of peak-displacement (TPD), and shear modulus (μ) as well as to identify the change of plasma samples during the clot formation process. The IARF-based ultrasonic system transmitted bursts with a frequency of 2.03 MHz, duration of 246.31 µs, amplitude of 118 VPP, and pulse with 1.25 Hz repetition frequency to generate an IARF on a glass sphere (2.99 mm in diameter and 2500 kg/m3 in density) embedded in a plasma sample, causing a displacement that was monitored by a pulse-echo system with a center frequency of 4.89 MHz. The values of the shear moduli were 124.14 ± 3.02, 556.99 ± 11.76, and 670.39 ± 9.77 Pa, for fibrinogen concentrations of 1.2, 2.4, and 3.6 g/L 20 to 36 min after the beginning of the coagulation process. The TPD values obtained in the same period were 5.28 ± 0.09, 3.03 ± 0.02, and 2.83 ± 0.01 s. The results indicate that an IARF-based ultrasonic system can be used clinically because it uses small amounts of plasma and has the ability to detect differences in PD, TPD, and μ as a function of fibrinogen concentrations.
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Affiliation(s)
- José Francisco Silva Costa-Júnior
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Brazilian Air Force Academy, Pirassununga, SP, Brazil.
| | - João Carlos Machado
- Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Post-Graduation Program on Surgical Sciences-School of Medicine/Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Retrieved cerebral thrombi studied by T2 and ADC mapping: preliminary results. Radiol Oncol 2019; 53:427-433. [PMID: 31747380 PMCID: PMC6884935 DOI: 10.2478/raon-2019-0056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 10/22/2019] [Indexed: 01/01/2023] Open
Abstract
Background Recent advances in MRI technology makes it increasingly more competitive to CT also in the field of interventions. Multi-parametric MRI offers a significant amount of data relevant for characterization of human cerebral thrombi. Patients and methods Cerebral thrombi of 17 patients diagnosed with acute stroke were acquired by mechanical thrombectomy. The thrombi were subsequently scanned using a high spatial-resolution 3D T1-weighted MRI to obtain morphological characteristics of the thrombi and also by apparent diffusion coefficient (ADC) and transversal nuclear magnetic resonance (NMR) relaxation time (T2) mapping. The MRI results were analysed for possible correlations between thrombectomy procedure parameters (recanalization time and number of passes) and MR-measurable parameters (sample-mean ADC and T2, within-sample coefficient of variation of ADC and T2, and thrombus length). Results Both MRI mapping techniques enabled a good discrimination among thrombi regions of different water mobility and compaction. Within-sample coefficient of variation of ADC was found most sensitive for discrimination between the thrombi where thrombectomy procedure was performed in a single pass and those where is was performed in two or more passes (p = 0.03). Interestingly, negative correlation was found between the recanalization time and thrombus length (ρ = -0.22). Conclusions Preliminary results of presented study shows that pretreatment MRI assessment of thrombi in stroke patients could potentially ease stroke treatment planning. In this study it is shown that within-sample coefficient of variation of ADC could serve for prediction of possible complications during thrombectomy procedures.
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Sharma AK, Reis J, Oppenheimer DC, Rubens DJ, Ormachea J, Hah Z, Parker KJ. Attenuation of Shear Waves in Normal and Steatotic Livers. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:895-901. [PMID: 30685077 DOI: 10.1016/j.ultrasmedbio.2018.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/29/2018] [Accepted: 12/08/2018] [Indexed: 06/09/2023]
Abstract
Shear wave propagation in the liver has been a robust subject of research, with shear wave speed receiving the most attention. The correlation between increased shear wave speed and increased fibrosis in the liver has been established as a useful diagnostic tool. In comparison, the precise mechanisms of shear wave attenuation, and its relation to diseased states of the liver, are less well-established. This study focused on the hypothesis that steatosis adds a viscous (lossy) component to the liver, which increases shear wave attenuation. Twenty patients' livers were scanned with ultrasound and with induced shear wave propagation, and the resulting displacement profiles were analyzed using recently developed estimators to derive both the speed and attenuation of the shear waves within 6-cm2 regions of interest. The results were compared with pathology scores obtained from liver biopsies taken under ultrasound guidance. Across these cases, increases in shear wave attenuation were linked to increased steatosis score. This preliminary study supports the hypothesis and indicates the possible utility of the measurements for non-invasive and quantitative assessment of steatosis.
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Affiliation(s)
- Ashwani K Sharma
- Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA
| | - Joseph Reis
- Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA
| | - Daniel C Oppenheimer
- Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA
| | - Deborah J Rubens
- Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA
| | - Juvenal Ormachea
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York, USA
| | | | - Kevin J Parker
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York, USA.
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Ivlev DA, Shirinli SN, Guria KG, Uzlova SG, Guria GT. Control of fibrinolytic drug injection via real-time ultrasonic monitoring of blood coagulation. PLoS One 2019; 14:e0211646. [PMID: 30811424 PMCID: PMC6392241 DOI: 10.1371/journal.pone.0211646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/17/2019] [Indexed: 12/02/2022] Open
Abstract
In the present study, we investigated the capabilities of a novel ultrasonic approach for real-time control of fibrinolysis under flow conditions. Ultrasonic monitoring was performed in a specially designed experimental in vitro system. Fibrinolytic agents were automatically injected at ultrasonically determined stages of the blood clotting. The following clots dissolution in the system was investigated by means of ultrasonic monitoring. It was shown, that clots resistance to fibrinolysis significantly increases during the first 5 minutes since the formation of primary micro-clots. The efficiency of clot lysis strongly depends on the concentration of the fibrinolytic agent as well as the delay of its injection moment. The ultrasonic method was able to detect the coagulation at early stages, when timely pharmacological intervention can still prevent the formation of macroscopic clots in the experimental system. This result serves as evidence that ultrasonic methods may provide new opportunities for real-time monitoring and the early pharmacological correction of thrombotic complications in clinical practice.
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Affiliation(s)
| | | | | | | | - Georgy Th. Guria
- National Research Center for Hematology, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- * E-mail:
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15
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Mercado-Shekhar KP, Kleven RT, Aponte Rivera H, Lewis R, Karani KB, Vos HJ, Abruzzo TA, Haworth KJ, Holland CK. Effect of Clot Stiffness on Recombinant Tissue Plasminogen Activator Lytic Susceptibility in Vitro. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:2710-2727. [PMID: 30268531 PMCID: PMC6551517 DOI: 10.1016/j.ultrasmedbio.2018.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 08/01/2018] [Accepted: 08/10/2018] [Indexed: 05/05/2023]
Abstract
The lytic recombinant tissue plasminogen activator (rt-PA) is the only drug approved by the Food and Drug Administration for treating ischemic stroke. Less than 40% of patients with large vessel occlusions who are treated with rt-PA have improved blood flow. However, up to 6% of all patients receiving rt-PA develop intracerebral hemorrhage. Predicting the efficacy of rt-PA treatment a priori could help guide therapeutic decision making, such that rt-PA is administered only to those individuals who would benefit from this treatment. Clot composition and structure affect the lytic efficacy of rt-PA and have an impact on elasticity. However, the relationship between clot elasticity and rt-PA lytic susceptibility has not been adequately investigated. The goal of this study was to quantify the relationship between clot elasticity and rt-PA susceptibility in vitro. Human and porcine highly retracted and mildly retracted clots were fabricated in glass pipettes. The rt-PA lytic susceptibility was evaluated in vitro using the percent clot mass loss. The Young's moduli of the clots were estimated using ultrasound-based single-track-location shear wave elasticity imaging. The percent mass loss in mildly retracted porcine and human clots (28.9 ± 6.1% and 45.2 ± 7.1%, respectively) was significantly higher (p < 0.05) than in highly retracted porcine and human clots (10.9 ± 2.1% and 25.5 ± 10.0%, respectively). Furthermore, the Young's moduli of highly retracted porcine and human clots (5.33 ± 0.92 and 3.21 ± 1.97 kPa, respectively) were significantly higher (p < 0.05) than those of mildly retracted porcine and human clots (2.66 ± 0.55 and 0.79 ± 0.21 kPa, respectively). The results revealed an inverse relationship between the percent clot mass loss and Young's modulus. These findings motivate continued investigation of ultrasound-based methods to assess clot stiffness in order to predict rt-PA thrombolytic efficacy.
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Affiliation(s)
- Karla P Mercado-Shekhar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
| | - Robert T Kleven
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Hermes Aponte Rivera
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Ryden Lewis
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kunal B Karani
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Hendrik J Vos
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Todd A Abruzzo
- Department of Radiology, Cincinnati Children's Hospital, Cincinnati, Ohio, USA
| | - Kevin J Haworth
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Christy K Holland
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
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Bhatt M, Montagnon E, Destrempes F, Chayer B, Kazemirad S, Cloutier G. Acoustic radiation force induced resonance elastography of coagulating blood: theoretical viscoelasticity modeling and ex-vivo experimentation. Phys Med Biol 2018; 63:065018. [PMID: 29509143 DOI: 10.1088/1361-6560/aab46a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Deep vein thrombosis is a common vascular disease that can lead to pulmonary embolism and death. The early diagnosis and clot age staging are important parameters for reliable therapy planning. This article presents an acoustic radiation force induced resonance elastography method for the viscoelastic characterization of clotting blood. The physical concept of this method relies on the mechanical resonance of the blood clot occurring at specific frequencies. Resonances are induced by focusing ultrasound beams inside the sample under investigation. Coupled to an analytical model of wave scattering, the ability of the proposed method to characterize the viscoelasticity of a mimicked venous thrombosis in the acute phase is demonstrated. Experiments with a gelatin-agar inclusion sample of known viscoelasticity are performed for validation and establishment of the proof of concept. In addition, an inversion method is applied in-vitro for the kinetic monitoring of the blood coagulation process of six human blood samples obtained from two volunteers. The computed elasticity and viscosity values of blood samples at the end of the 90 min kinetics were estimated at 411 ± 71 Pa and 0.25 ± 0.03 Pa.s for volunteer #1, and 387 ± 35 Pa and 0.23 ± 0.02 Pa.s for volunteer #2, respectively. The proposed method allowed reproducible time-varying thrombus viscoelastic measurements from samples having physiological dimensions.
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Affiliation(s)
- Manish Bhatt
- Centre Hospitalier de L'Universite de Montreal, Montreal, Quebec, H2W 1T8, CANADA
| | - Emmanuel Montagnon
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center, Montreal, Quebec, CANADA
| | - Francois Destrempes
- Laboratory of Biorheology and Medical Ultrasonics Research Center Univeristy of Montreal Hospital, Universite de Montreal, Montreal, CANADA
| | - Boris Chayer
- University of Montreal Hospital Research Center, Montreal, CANADA
| | - Siavash Kazemirad
- Iran University of Science and Technology, Tehran, Tehran, Iran (the Islamic Republic of)
| | - Guy Cloutier
- Laboratory of Biorheology and Medical Ultrasonics , University of Montreal Hospital Research Center, 900 St-Denis, Montreal, Quebec, CANADA
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17
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Yaraş YS, Gündüz AB, Sağlam G, Ölçer S, Civitçi F, Baris İ, Yaralioğlu G, Urey H. Coagulation measurement from whole blood using vibrating optical fiber in a disposable cartridge. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-8. [PMID: 29127692 DOI: 10.1117/1.jbo.22.11.117001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 10/12/2017] [Indexed: 06/07/2023]
Abstract
In clinics, blood coagulation time measurements are performed using mechanical measurements with blood plasma. Such measurements are challenging to do in a lab-on-a-chip (LoC) system using a small volume of whole blood. Existing LoC systems use indirect measurement principles employing optical or electrochemical methods. We developed an LoC system using mechanical measurements with a small volume of whole blood without requiring sample preparation. The measurement is performed in a microfluidic channel where two fibers are placed inline with a small gap in between. The first fiber operates near its mechanical resonance using remote magnetic actuation and immersed in the sample. The second fiber is a pick-up fiber acting as an optical sensor. The microfluidic channel is engineered innovatively such that the blood does not block the gap between the vibrating fiber and the pick-up fiber, resulting in high signal-to-noise ratio optical output. The control plasma test results matched well with the plasma manufacturer's datasheet. Activated-partial-thromboplastin-time tests were successfully performed also with human whole blood samples, and the method is proven to be effective. Simplicity of the cartridge design and cost of readily available materials enable a low-cost point-of-care device for blood coagulation measurements.
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Affiliation(s)
- Yusuf Samet Yaraş
- Koc University, College of Engineering, Department of Electrical and Electronics Engineering, Istanb, Turkey
| | - Ali Bars Gündüz
- Koc University, College of Engineering, Department of Electrical and Electronics Engineering, Istanb, Turkey
| | - Gökhan Sağlam
- Koc University, College of Engineering, Department of Electrical and Electronics Engineering, Istanb, Turkey
| | - Selim Ölçer
- Koc University, College of Engineering, Department of Electrical and Electronics Engineering, Istanb, Turkey
| | - Fehmi Civitçi
- Istanbul Technical University, Department of Electronics and Communication Engineering, Faculty of E, Turkey
| | - İbrahim Baris
- Koc University, College of Sciences, Department of Molecular Biology and Genetics, Istanbul, Turkey
| | - Göksenin Yaralioğlu
- Ozyegin University, Faculty of Engineering, Department of Electrical and Electronics Engineering, Is, Turkey
| | - Hakan Urey
- Koc University, College of Engineering, Department of Electrical and Electronics Engineering, Istanb, Turkey
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18
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Liu X, Li N, Wen C. Effect of pathological heterogeneity on shear wave elasticity imaging in the staging of deep venous thrombosis. PLoS One 2017; 12:e0179103. [PMID: 28614362 PMCID: PMC5470690 DOI: 10.1371/journal.pone.0179103] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 05/24/2017] [Indexed: 11/27/2022] Open
Abstract
Background We aimed to observe the relationship between the pathological components of a deep venous thrombus (DVT), which was divided into three parts, and the findings on quantitative ultrasonic shear wave elastography (SWE) to increase the accuracy of thrombus staging in a rabbit model. Methods A flow stenosis-induced vein thrombosis model was used, and the thrombus was divided into three parts (head, body and tail), which were associated with corresponding observation points. Elasticity was quantified in vivo using SWE over a 2-week period. A quantitative pathologic image analysis (QPIA) was performed to obtain the relative percentages of the components of the main clots. Results DVT maturity occurred at 2 weeks, and the elasticity of the whole thrombus and the three parts (head, body and tail) showed an increasing trend, with the Young's modulus values varying from 2.36 ± 0.41 kPa to 13.24 ± 1.71 kPa; 2.01 ± 0.28 kPa to 13.29 ± 1.48 kPa; 3.27 ± 0.57 kPa to 15.91 ± 2.05 kPa; and 1.79 ± 0.36 kPa to 10.51 ± 1.61 kPa, respectively. Significant increases occurred on different days for the different parts: the head showed significant increases on days 4 and 6; the body showed significant increases on days 4 and 7; and the tail showed significant increases on days 3 and 6. The QPIA showed that the thrombus composition changed dynamically as the thrombus matured, with the fibrin and calcium salt deposition gradually increasing and the red blood cells (RBCs) and platelet trabecula gradually decreasing. Significant changes were observed on days 4 and 7, which may represent the transition points for acute, sub-acute and chronic thrombi. Significant heterogeneity was observed between and within the thrombi. Conclusions Variations in the thrombus components were generally consistent between the SWE and QPIA. Days 4 and 7 after thrombus induction may represent the transition points for acute, sub-acute and chronic thrombi in rabbit models. A dynamic examination of the same part of the thrombus may be helpful for improving the sensitivity and reproducibility of SWE for DVT diagnosis and staging.
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Affiliation(s)
- Xiaona Liu
- Chinese PLA (People's Liberation Army) Medical School, Beijing, P.R. China
- Department of Ultrasound, Binzhou Medical University Hospital, Binzhou, Shandong, P.R. China
| | - Na Li
- Chinese PLA (People's Liberation Army) Medical School, Beijing, P.R. China
- Department of Auxiliary Diagnosis, The 463rd Hospital of Shenyang Military Region, Shenyang, Liaoning, P.R. China
| | - Chaoyang Wen
- Chinese PLA (People's Liberation Army) Medical School, Beijing, P.R. China
- Department of Ultrasound, The First Affiliated Hospital of Chinese PLA General Hospital, Beijing, P.R. China
- * E-mail:
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19
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Júnior JFSC, Parcero GC, Machado JC. Comparison analysis of four processing methods employed in dynamic elastography to estimate viscoelastic parameters of a medium: tests using computational simulation and experiment. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa61b9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Budelli E, Brum J, Bernal M, Deffieux T, Tanter M, Lema P, Negreira C, Gennisson JL. A diffraction correction for storage and loss moduli imaging using radiation force based elastography. Phys Med Biol 2016; 62:91-106. [PMID: 27973354 DOI: 10.1088/1361-6560/62/1/91] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Noninvasive evaluation of the rheological behavior of soft tissues may provide an important diagnosis tool. Nowadays, available commercial ultrasound systems only provide shear elasticity estimation by shear wave speed assessment under the hypothesis of a purely elastic model. However, to fully characterize the rheological behavior of tissues, given by its storage (G') and loss (G″) moduli, it is necessary to estimate both: shear wave speed and shear wave attenuation. Most elastography techniques use the acoustic radiation force to generate shear waves. For this type of source the shear waves are not plane and a diffraction correction is needed to properly estimate the shear wave attenuation. The use of a cylindrical wave approximation to evaluate diffraction has been proposed by other authors before. Here the validity of such approximation is numerically and experimentally revisited. Then, it is used to generate images of G' and G″ in heterogeneous viscoelastic mediums. A simulation algorithm based on the anisotropic and viscoelastic Green's function was used to establish the validity of the cylindrical approximation. Moreover, two experiments were carried out: a transient elastography experiment where plane shear waves were generated using a vibrating plate and a SSI experiment that uses the acoustic radiation force to generate shear waves. For both experiments the shear wave propagation was followed with an ultrafast ultrasound scanner. Then, the shear wave velocity and shear wave attenuation were recovered from the phase and amplitude decay versus distance respectively. In the SSI experiment the cylindrical approximation was applied to correct attenuation due to diffraction effects. The numerical and experimental results validate the use of a cylindrical correction to assess shear wave attenuation. Finally, by applying the cylindrical correction G' and G″ images were generated in heterogeneous phantoms and a preliminary in vivo feasibility study was carried out in the human liver.
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Affiliation(s)
- Eliana Budelli
- InstitutLangevin-Ondes et Images, ESPCI Paris, PSL Research University, CNRS UMR 7587, INSERM U979, Université Paris Denis Diderot, 17 rue Moreau, 75012 Paris, France. Instituto de Ingeniería Química, Facultad de Ingeniería, Universidad de la República, Julio Herrera y Reissig 565, CP 11300 Montevideo, Uruguay
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21
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Carstensen EL, Parker KJ. Oestreicher and elastography. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:2317-25. [PMID: 26520312 DOI: 10.1121/1.4930953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A sphere moving back and forth in tissue generates the kinds of complex displacement fields that are used in elastography. The analytical solution of Hans Oestreicher for this phenomenon [(1951). J. Acoust. Soc. Am. 23, 704-714] gives an understanding of the transverse and longitudinal, fast and slow waves that are generated. The results suggest several ways to determine the absorption coefficients of tissues, which together with phase velocity permit the computation of both the real shear modulus and the shear viscosity as functions of frequency.
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Affiliation(s)
- Edwin L Carstensen
- Departments of Electrical & Computer and of Biomedical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Kevin J Parker
- Departments of Electrical & Computer and of Biomedical Engineering, University of Rochester, Rochester, New York 14627, USA
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22
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Wang CW, Perez MJ, Helmke BP, Viola F, Lawrence MB. Integration of acoustic radiation force and optical imaging for blood plasma clot stiffness measurement. PLoS One 2015; 10:e0128799. [PMID: 26042775 PMCID: PMC4456080 DOI: 10.1371/journal.pone.0128799] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 04/30/2015] [Indexed: 01/22/2023] Open
Abstract
Despite the life-preserving function blood clotting serves in the body, inadequate or excessive blood clot stiffness has been associated with life-threatening diseases such as stroke, hemorrhage, and heart attack. The relationship between blood clot stiffness and vascular diseases underscores the importance of quantifying the magnitude and kinetics of blood's transformation from a fluid to a viscoelastic solid. To measure blood plasma clot stiffness, we have developed a method that uses ultrasound acoustic radiation force (ARF) to induce micron-scaled displacements (1-500 μm) on microbeads suspended in blood plasma. The displacements were detected by optical microscopy and took place within a micro-liter sized clot region formed within a larger volume (2 mL sample) to minimize container surface effects. Modulation of the ultrasound generated acoustic radiation force allowed stiffness measurements to be made in blood plasma from before its gel point to the stage where it was a fully developed viscoelastic solid. A 0.5 wt % agarose hydrogel was 9.8-fold stiffer than the plasma (platelet-rich) clot at 1 h post-kaolin stimulus. The acoustic radiation force microbead method was sensitive to the presence of platelets and strength of coagulation stimulus. Platelet depletion reduced clot stiffness 6.9 fold relative to platelet rich plasma. The sensitivity of acoustic radiation force based stiffness assessment may allow for studying platelet regulation of both incipient and mature clot mechanical properties.
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Affiliation(s)
- Caroline W. Wang
- Department of Biomedical Engineering, School of Engineering and Applied Science and School of Medicine, University of Virginia Health System, Charlottesville, Virginia, United States of America
| | - Matthew J. Perez
- Department of Biomedical Engineering, School of Engineering and Applied Science and School of Medicine, University of Virginia Health System, Charlottesville, Virginia, United States of America
| | - Brian P. Helmke
- Department of Biomedical Engineering, School of Engineering and Applied Science and School of Medicine, University of Virginia Health System, Charlottesville, Virginia, United States of America
| | - Francesco Viola
- HemoSonics, LLC, Charlottesville, Virginia, United States of America
| | - Michael B. Lawrence
- Department of Biomedical Engineering, School of Engineering and Applied Science and School of Medicine, University of Virginia Health System, Charlottesville, Virginia, United States of America
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Liu Y, Wu G, Wei H, Guo Z, Yang H, He Y, Xie S, Zhang Y, Zhu Z. In vitro assessment of effects of hyperglycemia on the optical properties of blood during coagulation using optical coherence tomography. Lasers Med Sci 2014; 30:413-20. [PMID: 25380667 DOI: 10.1007/s10103-014-1679-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 10/16/2014] [Indexed: 10/24/2022]
Abstract
No published reports have demonstrated the capability of the optical coherence tomography technique for quantifying the optical coherence tomography signal slope, 1/e light penetration depth, and attenuation coefficient of hyperglycemic blood by an in vitro assessment. The purpose of this study was to investigate the effects of hyperglycemia on optical properties during in vitro blood coagulation by optical coherence tomography. Normal whole blood acted as the control group. After 1-h coagulation, the average optical coherence tomography signal slope decreased approximately 23.3 and 16.7%, and the 1/e light penetration depths increased approximately 21.5 and 19.2% for the control and hyperglycemic groups, respectively. It could be seen from the 1/e light penetration depth evolution curves that the blood coagulation time was about (425 ± 19) s for normal whole blood and (367 ± 15) s for the hyperglycemic blood. The coagulation time decreased 13.6% for the hyperglycemic blood compared with that for normal whole blood. There was statistically significant difference in blood coagulation time between the hyperglycemic and normal whole blood (p < 0.05). The results suggested that hyperglycemia has a procoagulant effect. Our experiment was the first reported study of monitoring hyperglycemic blood coagulation using OCT. We conclude that OCT is potential technique to quantify and follow the liquid-gel transition of hyperglycemic blood coagulation.
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Affiliation(s)
- Ying Liu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, Guangdong Province, China
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Abstract
A number of advances, including imaging of tissue displacements, have increased our ability to make measurements of tissue elastic properties of animal and human tissues. Accordingly, the question is increasingly asked, 'should our data be fit to a viscoelastic model, and if so which one?' In this paper we focus solely on soft tissues in a functional (non-pathological) state, and develop a model of elastic behavior that is based on the flow of viscous fluids through the extensive network of tissue microchannels in response to applied stress. This behavior can be captured in a 2-parameter model, and the model appears to predict the stress-relaxation behavior and the dispersive shear wave behavior of bovine liver specimens and other soft tissues and phantoms. The relationship of the microchannel flow model to more traditional models is also examined.
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Affiliation(s)
- K J Parker
- Department of Electrical and Computer Engineering, University of Rochester, Hopeman Building 203, PO Box 270126, Rochester, NY, 14627-0126, USA
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26
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Tripathi MM, Hajjarian Z, Van Cott EM, Nadkarni SK. Assessing blood coagulation status with laser speckle rheology. BIOMEDICAL OPTICS EXPRESS 2014; 5:817-31. [PMID: 24688816 PMCID: PMC3959840 DOI: 10.1364/boe.5.000817] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/30/2013] [Accepted: 01/02/2014] [Indexed: 05/23/2023]
Abstract
We have developed and investigated a novel optical approach, Laser Speckle Rheology (LSR), to evaluate a patient's coagulation status by measuring the viscoelastic properties of blood during coagulation. In LSR, a blood sample is illuminated with laser light and temporal speckle intensity fluctuations are measured using a high-speed CMOS camera. During blood coagulation, changes in the viscoelastic properties of the clot restrict Brownian displacements of light scattering centers within the sample, altering the rate of speckle intensity fluctuations. As a result, blood coagulation status can be measured by relating the time scale of speckle intensity fluctuations with clinically relevant coagulation metrics including clotting time and fibrinogen content. Our results report a close correlation between coagulation metrics measured using LSR and conventional coagulation results of activated partial thromboplastin time, prothrombin time and functional fibrinogen levels, creating the unique opportunity to evaluate a patient's coagulation status in real-time at the point of care.
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Affiliation(s)
- Markandey M. Tripathi
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Zeinab Hajjarian
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Elizabeth M. Van Cott
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02144, USA
| | - Seemantini K. Nadkarni
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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27
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The pathophysiology, diagnosis and treatment of the acute coagulopathy of trauma and shock: a literature review. Eur J Trauma Emerg Surg 2013; 41:259-72. [DOI: 10.1007/s00068-013-0360-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 12/01/2013] [Indexed: 10/25/2022]
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Bernal M, Gennisson JL, Flaud P, Tanter M. Correlation between classical rheometry and supersonic shear wave imaging in blood clots. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:2123-2136. [PMID: 23972484 DOI: 10.1016/j.ultrasmedbio.2013.05.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 04/19/2013] [Accepted: 05/23/2013] [Indexed: 06/02/2023]
Abstract
The assessment of coagulating blood elasticity has gained importance as a result of several studies that have correlated it to cardiovascular pathologic conditions. In this study we use supersonic shear wave imaging (SSI) to measure viscoelastic properties of blood clots. At the same time, classical rheometry experiments were carried out on the same blood samples taken within the first few seconds of coagulation. Using SSI, phase velocities of the shear wave indicated increasing dispersion with time. In all cases, the frequency bandwidth of propagating shear waves changed from 20-50 Hz at the first few min of coagulation to around 300 Hz toward the end of experiments. Using the values of G' and G″ from the rheometry studies, the theoretical shear wave velocities were calculated and correlated with SSI measurements. Results of the two techniques were in very good agreement, confirming that SSI provides accurate measurements of viscoelastic properties as corroborated by conventional rheometric measurements.
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Affiliation(s)
- Miguel Bernal
- Institut Langevin - Ondes et Images, ESPCI ParisTech, CNRS UMR 7587, INSERM U979, Paris, France
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Sarvazyan AP, Urban MW, Greenleaf JF. Acoustic waves in medical imaging and diagnostics. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1133-46. [PMID: 23643056 PMCID: PMC3682421 DOI: 10.1016/j.ultrasmedbio.2013.02.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 12/13/2012] [Accepted: 02/12/2013] [Indexed: 05/03/2023]
Abstract
Up until about two decades ago acoustic imaging and ultrasound imaging were synonymous. The term ultrasonography, or its abbreviated version sonography, meant an imaging modality based on the use of ultrasonic compressional bulk waves. Beginning in the 1990s, there started to emerge numerous acoustic imaging modalities based on the use of a different mode of acoustic wave: shear waves. Imaging with these waves was shown to provide very useful and very different information about the biological tissue being examined. We discuss the physical basis for the differences between these two basic modes of acoustic waves used in medical imaging and analyze the advantages associated with shear acoustic imaging. A comprehensive analysis of the range of acoustic wavelengths, velocities and frequencies that have been used in different imaging applications is presented. We discuss the potential for future shear wave imaging applications.
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Chueh JY, Kuhn AL, Wakhloo AK, Gounis MJ. Experimental Models of Vascular Occlusions for Evaluation of Thrombectomy Devices. Cardiovasc Eng Technol 2013. [DOI: 10.1007/s13239-013-0143-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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31
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Huang CC, Chen PY, Shih CC. Estimating the viscoelastic modulus of a thrombus using an ultrasonic shear-wave approach. Med Phys 2013; 40:042901. [DOI: 10.1118/1.4794493] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Schmitt C, Montagnon E, Henni AH, Qi S, Cloutier G. Shear wave induced resonance elastography of venous thrombi: a proof-of-concept. IEEE TRANSACTIONS ON MEDICAL IMAGING 2013; 32:565-577. [PMID: 23232414 DOI: 10.1109/tmi.2012.2231093] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Shear wave induced resonance elastography (SWIRE) is proposed for deep venous thrombosis (DVT) elasticity assessment. This new imaging technique takes advantage of properly polarized shear waves to induce resonance of a confined mechanical heterogeneity. Realistic phantoms (n = 9) of DVT total and partial clot occlusions with elasticities from 406 to 3561 Pa were built for in vitro experiments. An ex vivo study was also performed to evaluate the elasticity of two fresh porcine venous thrombi in a pig model. Transient shear waves at 45-205 Hz were generated by the vibration of a rigid plate (plane wavefront) or by a needle to simulate a radiation pressure on a line segment (cylindrical wavefront). Induced propagation of shear waves was imaged with an ultrafast ultrasound scanner and a finite element method was developed to simulate tested experimental conditions. An inverse problem was then formulated considering the first resonance frequency of the DVT inclusion. Elasticity agreements between SWIRE and a reference spectroscopy instrument (RheoSpectris) were found in vitro for total clots either in plane (r(2) = 0.989) or cylindrical (r(2) = 0.986) wavefront configurations. For total and partial clots, elasticity estimation errors were 9.0 ±4.6% and 9.3 ±11.3%, respectively. Ex vivo, the blood clot elasticity was 498 ±58 Pa within the inferior vena cava and 436 ±45 Pa in the right common iliac vein (p = 0.22). To conclude, the SWIRE technique seems feasible to quantitatively assess blood clot elasticity in the context of DVT ultrasound imaging.
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Affiliation(s)
- Cédric Schmitt
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, QC, Canada.
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Bernal M, Gennisson JL, Flaud P, Tanter M. Shear wave elastography quantification of blood elasticity during clotting. ULTRASOUND IN MEDICINE & BIOLOGY 2012; 38:2218-28. [PMID: 23069137 DOI: 10.1016/j.ultrasmedbio.2012.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/26/2012] [Accepted: 08/11/2012] [Indexed: 05/13/2023]
Abstract
Deep venous thrombosis (DVT) affects millions of people worldwide. A fatal complication occurs when the thrombi detach and create a pulmonary embolism. The diagnosis and treatment of DVT depends on clot's age. The elasticity of thrombi is closely related to its age. Blood was collected from pigs and anticoagulated using ethylenediaminetetraacetic acid (EDTA). Coagulation was initiated using calcium ions. Supersonic shear wave imaging was used to generate shear waves using 100 μs tone bursts of 8 MHz. Tracking of the shear waves was done by ultrafast imaging. Postprocessing of the data was done using Matlab(®). Two-dimensional (2-D) maps of elasticity were obtained by calculating the speed of shear wave propagation. Elasticity varied with time from around 50 Pa at coagulation to 1600 Pa at 120 min after which the elasticity showed a natural decreased (17%) because of thrombolytic action of plasmin. Ejection of the serum from the clot showed a significant decrease in the elasticity of the clot next to the liquid pool (65% decrease), corresponding to the detachment of the clot from the beaker wall. The use of a thrombolytic agent (Urokinase) on the coagulated blood decreased the shear elasticity close to the point of injection, which varied with time and distance. Supersonic imaging proved to be useful mapping the 2-D clot's elasticity. It allowed the visualization of the heterogeneity of mechanical properties of thrombi and has potential use in predicting thrombi breakage as well as in monitoring thrombolytic therapy.
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Affiliation(s)
- Miguel Bernal
- Institut Langevin, Ondes et Images, ESPCI ParisTech, CNRS UMR7587, INSERM U979, Paris, France.
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Mechano-rheological properties of the murine thrombus determined via nanoindentation and finite element modeling. J Mech Behav Biomed Mater 2012; 10:75-86. [DOI: 10.1016/j.jmbbm.2012.02.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 01/31/2012] [Accepted: 02/18/2012] [Indexed: 11/18/2022]
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Plag C, Mofid Y, Mateéo T, Callé R, Ossant F. High frequency ultrasound imaging of whole blood gelation and retraction during in vitro coagulation. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 131:4196-4202. [PMID: 22559391 DOI: 10.1121/1.3702431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Blood coagulation is a series of biochemical reactions resulting in the mechanical transformation of liquid blood into a gel. As a consequence, ultrasound, being mechanical waves, can provide specific details on the dynamics of coagulation. In fact, previous high-frequency ultrasound monitoring studies have shown drastic changes in ultrasound velocity and attenuation during whole blood coagulation and a model discussing the observed mechanical transformations was proposed. In this paper, a technique of visualization of the clotting mechanism is introduced, which complements and revises the previous hypotheses. This method is based on the monitoring of scatterers (red blood cells) movement through a time correlation of 20 MHZ rf signals. It allows the computing of both a displacement map revealing local details and disparities and a parameter quantifying the global structural behavior. Qualitative results for two typical samples show that the technique provides new insights on the gelation dynamics. A quantitative analysis computed from 12 healthy subjects found that the changes in the structural parameters are significantly correlated to the changes in velocity and attenuation, both dependent on the mechanical transformations in the sample. The previous model is therefore revised and a new way to measure gel and retraction times is proposed.
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Affiliation(s)
- Camille Plag
- UMRS INSERM U930, CNRS ERL 3106, Université François Rabelais de Tours, Equipe 5, France.
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36
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Vahidi B, Fatouraee N. Large deforming buoyant embolus passing through a stenotic common carotid artery: a computational simulation. J Biomech 2012; 45:1312-22. [PMID: 22365500 DOI: 10.1016/j.jbiomech.2012.01.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 01/13/2012] [Accepted: 01/16/2012] [Indexed: 11/25/2022]
Abstract
Arterial embolism is responsible for the death of lots of people who suffers from heart diseases. The major risk of embolism in upper limbs is that the ruptured particles are brought into the brain, thus stimulating neurological symptoms or causing the stroke. We presented a computational model using fluid-structure interactions (FSI) to investigate the physical motion of a blood clot inside the human common carotid artery. We simulated transportation of a buoyant embolus in an unsteady flow within a finite length tube having stenosis. Effects of stenosis severity and embolus size on arterial hemodynamics were investigated. To fulfill realistic nonlinear property of a blood clot, a rubber/foam model was used. The arbitrary Lagrangian-Eulerian formulation (ALE) and adaptive mesh method were used inside fluid domain to capture the large structural interfacial movements. The problem was solved by simultaneous solution of the fluid and the structure equations. Stress distribution and deformation of the clot were analyzed and hence, the regions of the embolus prone to lysis were localized. The maximum magnitude of arterial wall shear stress during embolism occurred at a short distance proximal to the throat of the stenosis. Through embolism, arterial maximum wall shear stress is more sensitive to stenosis severity than the embolus size whereas role of embolus size is more significant than the effect of stenosis severity on spatial and temporal gradients of wall shear stress downstream of the stenosis and on probability of clot lysis due to clot stresses while passing through the stenosis.
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Affiliation(s)
- Bahman Vahidi
- Department of Life Science Engineering, University of Tehran, Tehran, Iran
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37
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Urban MW, Chen S, Fatemi M. A Review of Shearwave Dispersion Ultrasound Vibrometry (SDUV) and its Applications. Curr Med Imaging 2012; 8:27-36. [PMID: 22866026 DOI: 10.2174/157340512799220625] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Measurement of tissue elasticity has emerged as an important advance in medical imaging and tissue characterization. However, soft tissue is inherently a viscoelastic material. One way to characterize the viscoelastic material properties of a material is to measure shear wave propagation velocities within the material at different frequencies and use the dispersion of the velocities, or variation with frequency, to solve for the material properties. Shearwave Dispersion Ultrasound Vibrometry (SDUV) is an ultrasound-based technique that uses this feature to characterize the viscoelastic nature of soft tissue. This method has been used to measure the shear elasticity and viscosity in various types of soft tissues including skeletal muscle, cardiac muscle, liver, kidney, prostate, and arterial vessels. This versatile technique provides measurements of viscoelastic material properties with high spatial and temporal resolution, which can be used for assessing these properties in normal and pathologic tissues. The goals of this paper are to 1) give an overview of viscoelasticity and shear wave velocity dispersion, 2) provide a history of the development of the SDUV method, and 3) survey applications for SDUV that have been previously reported.
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Affiliation(s)
- Matthew W Urban
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905
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38
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Sarvazyan A, Hall TJ, Urban MW, Fatemi M, Aglyamov SR, Garra BS. AN OVERVIEW OF ELASTOGRAPHY - AN EMERGING BRANCH OF MEDICAL IMAGING. Curr Med Imaging 2011; 7:255-282. [PMID: 22308105 PMCID: PMC3269947 DOI: 10.2174/157340511798038684] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
From times immemorial manual palpation served as a source of information on the state of soft tissues and allowed detection of various diseases accompanied by changes in tissue elasticity. During the last two decades, the ancient art of palpation gained new life due to numerous emerging elasticity imaging (EI) methods. Areas of applications of EI in medical diagnostics and treatment monitoring are steadily expanding. Elasticity imaging methods are emerging as commercial applications, a true testament to the progress and importance of the field.In this paper we present a brief history and theoretical basis of EI, describe various techniques of EI and, analyze their advantages and limitations, and overview main clinical applications. We present a classification of elasticity measurement and imaging techniques based on the methods used for generating a stress in the tissue (external mechanical force, internal ultrasound radiation force, or an internal endogenous force), and measurement of the tissue response. The measurement method can be performed using differing physical principles including magnetic resonance imaging (MRI), ultrasound imaging, X-ray imaging, optical and acoustic signals.Until recently, EI was largely a research method used by a few select institutions having the special equipment needed to perform the studies. Since 2005 however, increasing numbers of mainstream manufacturers have added EI to their ultrasound systems so that today the majority of manufacturers offer some sort of Elastography or tissue stiffness imaging on their clinical systems. Now it is safe to say that some sort of elasticity imaging may be performed on virtually all types of focal and diffuse disease. Most of the new applications are still in the early stages of research, but a few are becoming common applications in clinical practice.
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39
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Huang CC, Shih CC, Liu TY, Lee PY. Assessing the viscoelastic properties of thrombus using a solid-sphere-based instantaneous force approach. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:1722-33. [PMID: 21821355 DOI: 10.1016/j.ultrasmedbio.2011.06.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Revised: 06/24/2011] [Accepted: 06/27/2011] [Indexed: 05/13/2023]
Abstract
The viscoelastic properties of thrombus play a significant role when the clot closes a leak in a vessel of the blood circulation. The common method used to measure the viscoelastic properties of a clot employs a rheometer but this might be unsuitable due to the clot fiber network being broken up by excessive deformation. This study assessed the feasibility of using a novel acoustic method to assess the viscoelastic properties of blood clots. This method is based on monitoring the motion of a solid sphere in a blood clot induced by an applied instantaneous force. Experiments were performed in which a solid sphere was displaced by a 1 MHz single-element focused transducer, with a 20 MHz single-element focused transducer used to track this displacement. The spatiotemporal behavior of the sphere displacement was used to determine the viscoelastic properties of the clot. The experimental system was calibrated by measuring the viscoelastic modulus of gelatin using different types of solid spheres embedded in the phantoms and, then, the shear modulus and viscosity of porcine blood clots with hematocrits of 0% (plasma), 20% and 40% were assessed. The viscoelastic modulus of each clot sample was also measured directly by a rheometer for comparison. The results showed that the shear modulus increased from 173 ± 52 (mean ± SD) Pa for 40%-hematocrit blood clots to 619.5 ± 80.5 Pa for plasma blood clots, while the viscosity decreased from 0.32 ± 0.07 Pa∙s to 0.16 ± 0.06 Pa∙s, respectively, which indicated that the concentration of red blood cells and the amount of fibrinogen are the main determinants of the clot viscoelastic properties.
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Affiliation(s)
- Chih-Chung Huang
- Department of Electrical Engineering, Fu Jen Catholic University, Hsin Chuang District, Taipei, Taiwan.
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40
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Xu X, Lin J, Fu F. Optical coherence tomography to investigate optical properties of blood during coagulation. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:096002. [PMID: 21950916 DOI: 10.1117/1.3615667] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study investigates the optical properties of human blood during the coagulation process under statics using optical coherence tomography (OCT). OCT signal slope (OCTSS) and 1∕e light penetration depth (d(1∕e)) were obtained from the profiles of reflectance versus depth. Results showed that both OCTSS and d(1∕e) were able to sensitively differentiate various stages of blood properties during coagulating. After 1 h clotting, OCTSS decreased by 47.0%, 15.0%, 13.7%, and 8.5% and d(1∕e) increased by 34.7%, 29.4%, 24.3%, and 22.9% for the blood samples at HCT of 25%, 35%, 45%, and 55%, respectively. The slope of d(1∕e) versus time (S(r), ×10(-4) mm∕s), associated with clot formation rate decreased from 6.0 ± 0.3, 3.7 ± 0.5 to 2.3 ± 0.4 with the increasing of HCT from 35%, 45%, to 55%. The clotting time (t(c)) from the d(1∕e) evolution curves was estimated to be 1969 ± 92 s, 375 ± 12 s, 455 ± 11 s, and 865 ± 47 s for the blood of 25%, 35%, 45%, and 55%. This study demonstrates that the parameters (t(c) and S(r)) from the variations in d(1∕e) had better sensitivity and smaller standard deviation. Furthermore, blood hematocrit affecting backscattering properties of blood during coagulation was capable of being discerned by OCT parameters. It is concluded that OCT is a potential technique to quantify and follow the liquid-gel transition of blood during clotting.
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Affiliation(s)
- Xiangqun Xu
- Zhejiang Sci-Tech University, School of Science, Hangzhou 310018, China.
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41
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Van Houten EEW, Viviers DVR, McGarry MDJ, Perriñez PR, Perreard II, Weaver JB, Paulsen KD. Subzone based magnetic resonance elastography using a Rayleigh damped material model. Med Phys 2011; 38:1993-2004. [PMID: 21626932 DOI: 10.1118/1.3557469] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Recently, the attenuating behavior of soft tissue has been addressed in magnetic resonance elastography by the inclusion of a damping mechanism in the methods used to reconstruct the resulting mechanical property image. To date, this mechanism has been based on a viscoelastic model for material behavior. Rayleigh, or proportional, damping provides a more generalized model for elastic energy attenuation that uses two parameters to characterize contributions proportional to elastic and inertial forces. In the case of time-harmonic vibration, these two parameters lead to both the elastic modulus and the density being complex valued (as opposed to the case of pure viscoelasticity, where only the elastic modulus is complex valued). METHODS This article presents a description of Rayleigh damping in the time-harmonic case, discussing the differences between this model and the viscoelastic damping models. In addition, the results from a subzone based Rayleigh damped elastography study of gelatin and tofu phantoms are discussed, along with preliminary results from in vivo breast data. RESULTS Both the phantom and the tissue studies presented here indicate a change in the Rayleigh damping structure, described as Rayleigh composition, between different material types, with tofu and healthy tissue showing lower Rayleigh composition values than gelatin or cancerous tissue. CONCLUSIONS It is possible that Rayleigh damping elastography and the concomitant Rayleigh composition images provide a mechanism for differentiating tissue structure in addition to measuring elastic stiffness and attenuation. Such information could be valuable in the use of Rayleigh damped magnetic resonance elastography as a diagnostic imaging tool.
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Affiliation(s)
- Elijah E W Van Houten
- Department of Mechanical Engineering, University of Canterbury, Christchurch, Canterbury 8140, New Zealand.
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42
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Schmitt C, Hadj Henni A, Cloutier G. Characterization of blood clot viscoelasticity by dynamic ultrasound elastography and modeling of the rheological behavior. J Biomech 2010; 44:622-9. [PMID: 21122863 DOI: 10.1016/j.jbiomech.2010.11.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 11/08/2010] [Accepted: 11/10/2010] [Indexed: 11/29/2022]
Abstract
Dynamic elastography (DE) is a new tool to study mechanical behavior of soft tissues via their motion response to propagating shear waves. This technique characterized viscoelasticity of 9 porcine whole blood samples (3 animals) during coagulation for a shearing frequency of 70Hz, and after complete clot formation between 50 and 160Hz. Clot storage (G') and loss (G″) moduli were calculated from shear wave velocity and attenuation. Temporal evolutions of G' and G″ during coagulation were typified with 4 parameters: maximum change in elasticity (G' slope(max)), elasticity after 120min of coagulation (G'(max)), time occurrence of G″ maximum (t(e)) and G″ at the plateau (G″(plateau)). G' and G″ frequency dependence of completely formed blood clots was fitted with 5 standard rheological models: Maxwell, Kelvin-Voigt, Jeffrey, Zener and third-order generalized Maxwell. DE had sufficient sensitivity to follow the coagulation kinetics described by a progressive increase in G', while G″ transitory increased followed by a rapid stabilization. Inter- and intra-animal dispersions (InterAD and IntraAD) of G'(max) (InterAD=15.9%, IntraAD=9.1%) showed better reproducibility than G' slope(max) (InterAD=40.4%, IntraAD=21.9%), t(e) (InterAD=27.4%, IntraAD=18.7%) and G″(plateau) (InterAD=58.6%, IntraAD=40.2%). G' evolution within the considered range of frequency exhibited an increase, followed by stabilization to a plateau, whereas G″ presented little variations with convergence at a quasi-constant value at highest frequencies. Residues χ(⁎), describing the goodness of fit between models and experimental data, showed statistically (p<0.05) that the Kelvin-Voigt model was less in agreement with experimental data than other models. The Zener model is recommended to predict G' and G″ dispersion of coagulated blood over the explored frequency range.
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Affiliation(s)
- Cédric Schmitt
- Laboratory of Biorheology and Medical Ultrasonics, Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada H2L2W5
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43
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Mitri FG, Urban MW, Fatemi M, Greenleaf JF. Shear wave dispersion ultrasonic vibrometry for measuring prostate shear stiffness and viscosity: an in vitro pilot study. IEEE Trans Biomed Eng 2010; 58:235-42. [PMID: 20595086 DOI: 10.1109/tbme.2010.2053928] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This paper reports shear stiffness and viscosity "virtual biopsy" measurements of the three excised noncancerous human prostates using a new tool known as shear wave dispersion ultrasound vibrometry (SDUV) in vitro. Improved methods for prostate guided-biopsy are required to effectively guide needle biopsy to the suspected site. In addition, tissue stiffness measurement helps in identifying a suspected site to perform biopsy because stiffness has been shown to correlate with pathologies, such as cancerous tissue. More importantly, early detection of prostate cancer may guide minimally invasive therapy and eliminate insidious procedures. In this paper, "virtual biopsies" were taken in multiple locations in three excised prostates; SDUV shear elasticity and viscosity measurements were performed at the selected "suspicious" locations within the prostates. SDUV measurements of prostate elasticity and viscosity are generally in agreement with preliminary values previously reported in the literature. It is, however, important to emphasize here that the obtained viscoelastic parameters values are local, and not a mean value for the whole prostate.
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Affiliation(s)
- F G Mitri
- Department of Physiology and Biomedical Engineering,Mayo Clinic, Rochester, MN 55905 USA.
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45
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Peng HT, Shek PN. Development of in situ-forming hydrogels for hemorrhage control. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20:1753-1762. [PMID: 19347258 DOI: 10.1007/s10856-009-3721-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 02/17/2009] [Indexed: 05/27/2023]
Abstract
We report the preparation of in situ-forming hydrogels, composed of oxidized dextran (Odex) and amine-containing polymers, for their potential use as a wound dressing to promote blood clotting. Dextran was oxidized by sodium periodate to introduce aldehyde groups to form hydrogels, upon mixing in solution with different polymers containing primary amine groups, including polyallylamine (PAA), oligochitosan and glycol chitosan. A series of experiments were conducted to identify the optimum gelation condition for the Odex-PAA system. The polymer concentration appeared to have a major effect on gelation time and the polymer weight ratio affected the resulting gel content and swelling. Other influencing factors included pH of the buffer used to dissolve each polymer, PAA molecular weight, and the type of individual material. The latter also contributed significantly to gel content and swelling. Thromboelastography was used to examine the effects of the in situ gelation on blood coagulation in vitro, where the Odex-PAA combination was found to be most pro-hemostatic, as indicated by a decrease in clotting time and an increase in clot strength. The results of this study demonstrated that in situ-forming hydrogels could promote clotting in vitro; however, further studies are required to determine if the same hydrogel formulations are effective in controlling hemorrhage in vivo.
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Affiliation(s)
- Henry T Peng
- Defence Research and Development Canada - Toronto, Toronto, ON, Canada.
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46
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Urban MW, Chen S, Greenleaf JF. Error in estimates of tissue material properties from shear wave dispersion ultrasound vibrometry. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2009; 56:748-58. [PMID: 19406703 PMCID: PMC2756029 DOI: 10.1109/tuffc.2009.1097] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Shear wave velocity measurements are used in elasticity imaging to find the shear elasticity and viscosity of tissue. A technique called shear wave dispersion ultrasound vibrometry (SDUV) has been introduced to use the dispersive nature of shear wave velocity to locally estimate the material properties of tissue. Shear waves are created using a multifrequency ultrasound radiation force, and the propagating shear waves are measured a few millimeters away from the excitation point. The shear wave velocity is measured using a repetitive pulse-echo method and Kalman filtering to find the phase of the harmonic shear wave at 2 different locations. A viscoelastic Voigt model and the shear wave velocity measurements at different frequencies are used to find the shear elasticity (mu(1)) and viscosity (mu(2)) of the tissue. The purpose of this paper is to report the accuracy of the SDUV method over a range of different values of mu(1) and mu(2). A motion detection model of a vibrating scattering medium was used to analyze measurement errors of vibration phase in a scattering medium. To assess the accuracy of the SDUV method, we modeled the effects of phase errors on estimates of shear wave velocity and material properties while varying parameters such as shear stiffness and viscosity, shear wave amplitude, the distance between shear wave measurements (delta r), signal-to-noise ratio (SNR) of the ultrasound pulse-echo method, and the frequency range of the measurements. We performed an experiment in a section of porcine muscle to evaluate variation of the aforementioned parameters on the estimated shear wave velocity and material property measurements and to validate the error prediction model. The model showed that errors in the shear wave velocity and material property estimates were minimized by maximizing shear wave amplitude, pulse-echo SNR, delta r, and the bandwidth used for shear wave measurements. The experimental model showed optimum performance could be obtained for delta r = 3 - 6 mm, SNR =35 dB, with a frequency range of 100 to 600 Hz, and with a shear wave amplitude on the order of a few microns down to 0.5 microm. The model provides a basis to explore different parameters related to implementation of the SDUV method. The experiment confirmed conclusions made by the model, and the results can be used for optimization of SDUV.
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Affiliation(s)
- Matthew W Urban
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, USA.
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Peng HT, Blostein MD, Shek PN. Experimental optimization of anin situforming hydrogel for hemorrhage control. J Biomed Mater Res B Appl Biomater 2009; 89:199-209. [DOI: 10.1002/jbm.b.31206] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Callé R, Plag C, Patat F, Ossant F. Interest of the attenuation coefficient in multiparametric high frequency ultrasound investigation of whole blood coagulation process. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2009; 125:530-538. [PMID: 19173438 DOI: 10.1121/1.3021439] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Previous studies [R. Libgot, F. Ossant, Y. Gruel, P. Lermusiaux, and F. Patat, Proc.-IEEE Utrason. Symp. 4, 2259-2262 (2005); R. Libgot-Calle, F. Ossant, Y. Gruel, P. Lermusiaux, and F. Patat, Ultrasound Med. Biol. 34, 252-264 (2008); F. Ossant, R. Libgot, P. Coupe, P. Lermusiaux, and F. Patat, Proc.-IEEE Ultrason. Symp. 2, 846-849 (2004)] showed the potential of an in vitro high frequency ultrasound (beyond 20 MHz) device to describe the blood clotting process. The parameters were simultaneously estimated in double transmission (DT) with the calculation of the velocity of longitudinal waves and in backscattering (BS) modes with the estimation of the integrated BS coefficient and the effective scatterer size. The aim of the present study was to show how the integrated attenuation coefficient (IAC) assessed in DT mode could provide additional information on this process, especially regarding the fibrin polymerization which is an important part of the coagulation process. A characteristic time t(a) of the variations in IAC that could be linked to fibrin formation was identified.
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Affiliation(s)
- Rachel Callé
- Universite Francois Rabelais, INSERM U930, CNRS 2448 FRE, Tours, France.
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Uzlova SG, Guria KG, Guria GT. Acoustic determination of early stages of intravascular blood coagulation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2008; 366:3649-3661. [PMID: 18644769 DOI: 10.1098/rsta.2008.0109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The blood coagulation system (BCS) is a complex biological system playing a principal role in the maintenance of haemostasis. Insufficient activity of the BCS may lead to bleeding and blood loss (e.g. in the case of haemophilia). On the other hand, excessive activity may cause intravascular blood coagulation, thromboses and embolization. Most of the methods currently used for BCS monitoring suffer from the major disadvantage of being invasive. The purpose of the present work is to demonstrate the feasibility of using ultrasonic methods for non-invasive registration of the early stages of blood coagulation processes in intensive flows. With this purpose, a special experimental set-up was designed, facilitating the simultaneous detection of optical and acoustic signals during the clotting process. It was shown that (i) as microemboli appear in the flow during the early stage of blood coagulation, the intensity of the Doppler signal increases twofold, and (ii) microemboli formation in the early stages of blood clotting always reveals itself through an acoustic contrast. Both of these effects are well defined, so we hope that they may be used for non-invasive BCS monitoring in clinical practice.
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Henni AH, Schmitt C, Cloutier G. Three-dimensional transient and harmonic shear-wave scattering by a soft cylinder for dynamic vascular elastography. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2008; 124:2394-2405. [PMID: 19062877 DOI: 10.1121/1.2973194] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
With the objective of characterizing biological soft tissues with dynamic elastography, a three-dimensional (3D) analytical model is proposed to simulate the scattering of plane shear waves by a soft cylinder embedded in an infinite soft medium. The 3D problem of harmonic plane shear-wave scattering is first formulated and solved, and the monochromatic solution is employed to simulate transient wave scattering. Both harmonic and transient simulations are compared with experimental 3D acquisitions. The good agreements obtained between measured and calculated displacement fields allowed to conclude on the validity of the proposed 3D harmonic and transient models. The spatial distribution of displacements (diffraction lobes, displacement oscillations, wave diffraction angles, etc.) and their relative amplitudes in both inclusion and surrounding materials depended on the contrast between the viscoelastic properties of the different media. The possibility of solving an inverse problem to assess soft heterogeneous medium viscoelasticity is discussed and some future theoretical and experimental developments are proposed.
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Affiliation(s)
- Anis Hadj Henni
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center, Montreal, QC H2L 2W5, Canada.
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