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Li GY, Feng X, Yun SH. In Vivo Optical Coherence Elastography Unveils Spatial Variation of Human Corneal Stiffness. IEEE Trans Biomed Eng 2024; 71:1418-1429. [PMID: 38032780 PMCID: PMC11086014 DOI: 10.1109/tbme.2023.3338086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
OBJECTIVE The mechanical properties of corneal tissues play a crucial role in determining corneal shape and have significant implications in vision care. This study aimed to address the challenge of obtaining accurate in vivo data for the human cornea. METHODS We have developed a high-frequency optical coherence elastography (OCE) technique using shear-like antisymmetric (A0)-mode Lamb waves at frequencies above 10 kHz. RESULTS By incorporating an anisotropic, nonlinear constitutive model and utilizing the acoustoelastic theory, we gained quantitative insights into the influence of corneal tension on wave speeds and elastic moduli. Our study revealed significant spatial variations in the shear modulus of the corneal stroma on healthy subjects for the first time. Over an age span from 21 to 34 (N = 6), the central corneas exhibited a mean shear modulus of 87 kPa, while the corneal periphery showed a significant decrease to 44 kPa. The central cornea's shear modulus decreases with age with a slope of -19 +/- 8 kPa per decade, whereas the periphery showed non-significant age dependence. The limbus demonstrated an increased shear modulus exceeding 100 kPa. We obtained wave displacement profiles that are consistent with highly anisotropic corneal tissues. CONCLUSION Our approach enabled precise measurement of corneal tissue elastic moduli in situ with high precision (<7%) and high spatial resolution (<1 mm). Our results revealed significant stiffness variation from the central to peripheral corneas. SIGNIFICANCE The high-frequency OCE technique holds promise for biomechanical evaluation in clinical settings, providing valuable information for refractive surgeries, degenerative disorder diagnoses, and intraocular pressure assessments.
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Yin Z, Li GY, Zhang Z, Zheng Y, Cao Y. SWENet: A Physics-Informed Deep Neural Network (PINN) for Shear Wave Elastography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2024; 43:1434-1448. [PMID: 38032772 DOI: 10.1109/tmi.2023.3338178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Shear wave elastography (SWE) enables the measurement of elastic properties of soft materials in a non-invasive manner and finds broad applications in various disciplines. The state-of-the-art SWE methods rely on the measurement of local shear wave speeds to infer material parameters and suffer from wave diffraction when applied to soft materials with strong heterogeneity. In the present study, we overcome this challenge by proposing a physics-informed neural network (PINN)-based SWE (SWENet) method. The spatial variation of elastic properties of inhomogeneous materials has been introduced in the governing equations, which are encoded in SWENet as loss functions. Snapshots of wave motions have been used to train neural networks, and during this course, the elastic properties within a region of interest illuminated by shear waves are inferred simultaneously. We performed finite element simulations, tissue-mimicking phantom experiments, and ex vivo experiments to validate the method. Our results show that the shear moduli of soft composites consisting of matrix and inclusions of several millimeters in cross-section dimensions with either regular or irregular geometries can be identified with excellent accuracy. The advantages of the SWENet over conventional SWE methods consist of using more features of the wave motions and enabling seamless integration of multi-source data in the inverse analysis. Given the advantages of SWENet, it may find broad applications where full wave fields get involved to infer heterogeneous mechanical properties, such as identifying small solid tumors with ultrasound SWE, and differentiating gray and white matters of the brain with magnetic resonance elastography.
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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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Dwairy M, Reddy JN, Righetti R. Predicting stress and interstitial fluid pressure in tumors based on biphasic theory. Comput Biol Med 2023; 167:107651. [PMID: 37931527 DOI: 10.1016/j.compbiomed.2023.107651] [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: 05/15/2023] [Revised: 10/12/2023] [Accepted: 10/31/2023] [Indexed: 11/08/2023]
Abstract
The uncontrolled proliferation of cancer cells causes the growth of the tumor mass. Consequently, the normal surrounding tissue exerts a compressive force on the tumor mass to oppose its expansion. These stresses directly promote tumor metastasis and invasion and affect drug delivery. In the past, the mechanical behavior of solid tumors has been extensively studied using linear elastic and nonlinear hyperelastic constitutive models. In this study, we develop a two-dimensional biomechanical model based on the biphasic assumption of the solid matrix and fluid phase of the tissues. Heterogeneous vasculature and nonuniform blood perfusion are also investigated by incorporating in the model a necrotic core and a well-vascularized zone. The findings of our study demonstrate a significant difference between the linear and nonlinear tissue responses to stress, while the interstitial fluid pressure (IFP) distribution is found to be independent of the constitutive model. The proposed biphasic model may be useful for elasticity imaging techniques aiming at predicting stress and IFP in tumors.
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Affiliation(s)
- Mutaz Dwairy
- Department of Civil Engineering, Yarmouk University, Irbid, 21163, Jordan.
| | - J N Reddy
- Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA
| | - Raffaella Righetti
- Department of Electrical Engineering, Texas A&M University, College Station, TX, USA
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Saharkhiz N, Kamimura HAS, Konofagou EE. The impact of amplitude modulation frequency in harmonic motion imaging on inclusion characterization. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:1768-1779. [PMID: 37202245 PMCID: PMC10392769 DOI: 10.1016/j.ultrasmedbio.2023.03.025] [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: 05/04/2022] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 05/20/2023]
Abstract
OBJECTIVE Ultrasound elasticity imaging techniques aim to provide a non-invasive characterization of tissue mechanical properties to detect pathological changes and monitor disease progression. Harmonic motion imaging (HMI) is an ultrasound-based elasticity imaging technique that utilizes an oscillatory acoustic radiation force to induce localized displacements and estimate relative tissue stiffness. Previous studies have applied a low amplitude modulation (AM) frequency of 25 or 50 Hz in HMI to assess the mechanical properties of different tissue types. In this study, we investigate the dependence of AM frequency in HMI and whether the frequency can be adjusted based on the size and mechanical properties of the underlying medium for enhanced image contrast and inclusion detection. METHODS A tissue-mimicking phantom with embedded inclusions at different sizes and stiffnesses was imaged within a range of AM frequencies from 25 to 250 Hz at 25-Hz step size. DISCUSSION The AM frequency at which the maximum contrast and CNR are achieved depends on the size and stiffness of the inclusions. A general trend shows that contrast and CNR peak at higher frequencies for smaller inclusions. In addition, for some inclusions with the same size but different stiffnesses, the optimized AM frequency increases with the stiffness of the inclusion. Nevertheless, there is a shift between the frequencies at which the contrast peaks and those with maximum CNR. Finally, in agreement with the phantom findings, imaging an ex-vivo human specimen with a 2.7-cm breast tumor at a range of AM frequencies showed that the highest contrast and CNR are achieved at the AM frequency of 50 Hz. CONCLUSION These findings indicate that the AM frequency can be optimized in different applications of HMI, especially in the clinic, for improved detection and characterization of tumors with different geometries and mechanical properties.
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Affiliation(s)
- Niloufar Saharkhiz
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Hermes A S Kamimura
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Elisa E Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA; Department of Radiology, Columbia University, New York, NY 10027, USA.
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Saharkhiz N, Kamimura HAS, Konofagou EE. An Efficient and Multi-Focal Focused Ultrasound Technique for Harmonic Motion Imaging. IEEE Trans Biomed Eng 2023; 70:1150-1161. [PMID: 36191094 PMCID: PMC10067540 DOI: 10.1109/tbme.2022.3211465] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Harmonic motion imaging (HMI) is an ultrasound-based elasticity imaging technique that utilizes oscillatory acoustic radiation force to estimate the mechanical properties of tissues, as well as monitor high-intensity focused ultrasound (HIFU) treatment. Conventionally, in HMI, a focused ultrasound (FUS) transducer generates oscillatory tissue displacements, and an imaging transducer acquires channel data for displacement estimation, with each transducer being driven with a separate system. The fixed position of the FUS focal spot requires mechanical translation of the transducers, which can be a time-consuming and challenging procedure. In this study, we developed and characterized a new HMI system with a multi-element FUS transducer with the capability of electronic focal steering of ±5 mm and ±2 mm from the geometric focus in the axial and lateral directions, respectively. A pulse sequence was developed to drive both the FUS and imaging transducers using a single ultrasound data acquisition (DAQ) system. The setup was validated on a tissue-mimicking phantom with embedded inclusions. Integrating beam steering with the mechanical translation of the transducers resulted in a consistent high contrast-to-noise ratio (CNR) for the inclusions with Young's moduli of 22 and 44 kPa within a 5-kPa background while the data acquisition speed is increased by 4.5-5.2-fold compared to the case when only mechanical movements were applied. The feasibility of simultaneous generation of multiple foci and tracking the induced displacements is demonstrated in phantoms for applications where imaging or treatment of a larger region is needed. Moreover, preliminary feasibility is shown in a human subject with a breast tumor, where the mean HMI displacement within the tumor was about 4 times lower than that within perilesional tissues. The proposed HMI system facilitates data acquisition in terms of flexibility and speed and can be potentially used in the clinic for breast cancer imaging and treatment.
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Jerban S, Barrère V, Andre M, Chang EY, Shah SB. Quantitative Ultrasound Techniques Used for Peripheral Nerve Assessment. Diagnostics (Basel) 2023; 13:956. [PMID: 36900101 PMCID: PMC10000911 DOI: 10.3390/diagnostics13050956] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
AIM This review article describes quantitative ultrasound (QUS) techniques and summarizes their strengths and limitations when applied to peripheral nerves. METHODS A systematic review was conducted on publications after 1990 in Google Scholar, Scopus, and PubMed databases. The search terms "peripheral nerve", "quantitative ultrasound", and "elastography ultrasound" were used to identify studies related to this investigation. RESULTS Based on this literature review, QUS investigations performed on peripheral nerves can be categorized into three main groups: (1) B-mode echogenicity measurements, which are affected by a variety of post-processing algorithms applied during image formation and in subsequent B-mode images; (2) ultrasound (US) elastography, which examines tissue stiffness or elasticity through modalities such as strain ultrasonography or shear wave elastography (SWE). With strain ultrasonography, induced tissue strain, caused by internal or external compression stimuli that distort the tissue, is measured by tracking detectable speckles in the B-mode images. In SWE, the propagation speed of shear waves, generated by externally applied mechanical vibrations or internal US "push pulse" stimuli, is measured to estimate tissue elasticity; (3) the characterization of raw backscattered ultrasound radiofrequency (RF) signals, which provide fundamental ultrasonic tissue parameters, such as the acoustic attenuation and backscattered coefficients, that reflect tissue composition and microstructural properties. CONCLUSIONS QUS techniques allow the objective evaluation of peripheral nerves and reduce operator- or system-associated biases that can influence qualitative B-mode imaging. The application of QUS techniques to peripheral nerves, including their strengths and limitations, were described and discussed in this review to enhance clinical translation.
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Affiliation(s)
- Saeed Jerban
- Department of Radiology, University of California, San Diego, CA 92093, USA
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
- Department of Orthopaedic Surgery, University of California, San Diego, CA 92093, USA
| | - Victor Barrère
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
- Department of Orthopaedic Surgery, University of California, San Diego, CA 92093, USA
| | - Michael Andre
- Department of Radiology, University of California, San Diego, CA 92093, USA
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Eric Y. Chang
- Department of Radiology, University of California, San Diego, CA 92093, USA
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
| | - Sameer B. Shah
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA
- Department of Orthopaedic Surgery, University of California, San Diego, CA 92093, USA
- Department of Bioengineering, University of California, San Diego, CA 92093, USA
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Sebastian JA, Strohm EM, Baranger J, Villemain O, Kolios MC, Simmons CA. Assessing engineered tissues and biomaterials using ultrasound imaging: In vitro and in vivo applications. Biomaterials 2023; 296:122054. [PMID: 36842239 DOI: 10.1016/j.biomaterials.2023.122054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 01/24/2023] [Accepted: 02/11/2023] [Indexed: 02/18/2023]
Abstract
Quantitative assessment of the structural, functional, and mechanical properties of engineered tissues and biomaterials is fundamental to their development for regenerative medicine applications. Ultrasound (US) imaging is a non-invasive, non-destructive, and cost-effective technique capable of longitudinal and quantitative monitoring of tissue structure and function across centimeter to sub-micron length scales. Here we present the fundamentals of US to contextualize its application for the assessment of biomaterials and engineered tissues, both in vivo and in vitro. We review key studies that demonstrate the versatility and broad capabilities of US for clinical and pre-clinical biomaterials research. Finally, we highlight emerging techniques that further extend the applications of US, including for ultrafast imaging of biomaterials and engineered tissues in vivo and functional monitoring of stem cells, organoids, and organ-on-a-chip systems in vitro.
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Affiliation(s)
- Joseph A Sebastian
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada.
| | - Eric M Strohm
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
| | - Jérôme Baranger
- Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Olivier Villemain
- Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Michael C Kolios
- Department of Physics, Toronto Metropolitan University, Toronto, Canada; Institute of Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Canada
| | - Craig A Simmons
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
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Co-axial acoustic-based optical coherence vibrometry probe for the quantification of resonance frequency modes in ocular tissue. Sci Rep 2022; 12:18834. [PMID: 36336702 PMCID: PMC9637745 DOI: 10.1038/s41598-022-21978-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/07/2022] [Indexed: 11/08/2022] Open
Abstract
We present a co-axial acoustic-based optical coherence vibrometry probe (CoA-OCV) for vibro-acoustic resonance quantification in biological tissues. Sample vibrations were stimulated via a loudspeaker, and pre-compensation was used to calibrate the acoustic spectrum. Sample vibrations were measured via phase-sensitive swept-source optical coherence tomography (OCT). Resonance frequencies of corneal phantoms were measured at varying intraocular pressures (IOP), and dependencies on Young´s Modulus (E), phantom thickness and IOP were observed. Cycling IOP revealed hysteresis. For E = 0.3 MPa, resonance frequencies increased with IOP at a rate of 3.9, 3.7 and 3.5 Hz/mmHg for varied thicknesses and 1.7, 2.5 and 2.8 Hz/mmHg for E = 0.16 MPa. Resonance frequencies increased with thickness at a rate of 0.25 Hz/µm for E = 0.3 MPa, and 0.40 Hz/µm for E = 0.16 MPa. E showed the most predominant impact in the shift of the resonance frequencies. Full width at half maximum (FWHM) of the resonance modes increased with increasing thickness and decreased with increasing E. Only thickness and E contributed to the variance of FWHM. In rabbit corneas, resonance frequencies of 360-460 Hz were observed. The results of the current study demonstrate the feasibility of CoA-OCV for use in future OCT-V studies.
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Zheng E, Zhang H, Hu W, Doyley MM, Xia J. Volumetric tri-modal imaging with combined photoacoustic, ultrasound, and shear wave elastography. JOURNAL OF APPLIED PHYSICS 2022; 132:034902. [PMID: 35855685 PMCID: PMC9288268 DOI: 10.1063/5.0093619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Photoacoustic imaging is a hybrid imaging approach that combines the advantages of optical and ultrasonic imaging in one modality. However, for comprehensive tissue characterization, optical contrast alone is not always sufficient. In this study, we combined photoacoustic imaging with high-resolution ultrasound and shear wave elastography. The multi-modal system can calculate optical absorption, acoustic reflection, and stiffness volumetrically. We constructed a multi-modal phantom with contrast for each imaging modality to test the system's performance. Experimental results indicate that the system successfully visualizes the embedded structures. We envision that the system will lead to more comprehensive tissue characterization for cancer screening and diagnosis.
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Affiliation(s)
- Emily Zheng
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA
| | - Huijuan Zhang
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA
| | - Wentao Hu
- Department of Electrical and Computer Engineering, Rochester Center for Biomedical Ultrasound, University of Rochester, Rochester, New York 14627, USA
| | - Marvin M. Doyley
- Department of Electrical and Computer Engineering, Rochester Center for Biomedical Ultrasound, University of Rochester, Rochester, New York 14627, USA
| | - Jun Xia
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA
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Götschi T, Franchi MV, Schulz N, Fröhlich S, Frey WO, Snedeker JG, Spörri J. Altered regional 3D shear wave velocity patterns in youth competitive alpine skiers suffering from patellar tendon complaints - A prospective case-control study. Eur J Sport Sci 2022; 23:1068-1076. [PMID: 35699187 DOI: 10.1080/17461391.2022.2088404] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractPatellar tendon (PT) complaints are frequent throughout the population, with increased occurrence in athletes and, particularly, in youth competitive alpine skiers. Timely detection and treatment might improve prospects of recovery. Diagnostic modalities in clinical use to date rely on pain symptoms, manual palpation, and potentially, magnetic resonance imaging (MRI); however, MRI-based imaging yields limited sensitivity. Quantitatively measuring the morphological and mechanical properties of PTs by means of B-mode ultrasound and shear wave elastography (SWE), instead, may allow improved diagnosis or even early detection. We performed B-mode scans and three-dimensional ultrasound shear wave velocity (SWV) mapping and MRI of the PT in 106 youth skiers. A prospective one-year survey on health problems combined with clinical assessments served to categorize symptomatic and asymptomatic youth skiers. Skiers suffering from distal or proximal tendon complaints showed lower SWV in the respective tendon region than asymptomatic skiers (p = 0.035 and p = 0.019, respectively). Youth skiers with distal tendon complaints additionally exhibited decreased SWV in the proximal region compared to asymptomatic counterparts (p = 0.020). Cross-validated analysis of retrospective prediction indicated sensitivity and specificity in detecting tendon complaints in the range of 0.606-0.621 and 0.536-0.650, respectively. MRI detected distal tendon complaints with a sensitivity of 0.410 (12/29) but failed to detect any proximal cases. This study agrees with the most recent literature in that SWE holds promise as a valuable adjunct modality for the diagnosis of PT complaints or even the detection of subclinical prestages. However, to evaluate its prospective predictive value, long-term studies are warranted.
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Affiliation(s)
- Tobias Götschi
- Orthopaedic Biomechanics Laboratory, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland.,Institute for Biomechanics, ETH Zurich, Switzerland.,Sports Medical Research Group, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland
| | - Martino V Franchi
- Sports Medical Research Group, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland.,Institute of Physiology, Department of Biomedical Sciences, University of Padova, Padua, Italy
| | | | - Stefan Fröhlich
- Sports Medical Research Group, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland.,University Centre for Prevention and Sports Medicine, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland
| | - Walter O Frey
- Sports Medical Research Group, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland.,University Centre for Prevention and Sports Medicine, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland
| | - Jess G Snedeker
- Orthopaedic Biomechanics Laboratory, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland.,Institute for Biomechanics, ETH Zurich, Switzerland
| | - Jörg Spörri
- Sports Medical Research Group, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland.,University Centre for Prevention and Sports Medicine, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Switzerland
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Lin H, Chen Y, Xie S, Yu M, Deng D, Sun T, Hu Y, Chen M, Chen S, Chen X. A Dual-modal Imaging Method Combining Ultrasound and Electromagnetism for Simultaneous Measurement of Tissue Elasticity and Electrical Conductivity. IEEE Trans Biomed Eng 2022; 69:2499-2511. [PMID: 35119996 DOI: 10.1109/tbme.2022.3148120] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The mechanical and electrical properties of soft tissues are relative to soft tissues' pathological state. Modern medical imaging devices have shown a trend to multi-modal imaging, which will provide complementary functional information to improve the accuracy of disease diagnosis. However, no method or system can simultaneously measure the mechanical and electrical properties of the soft tissue. In this study, we proposed a novel dual-modal imaging method integrated by shear wave elasticity imaging (SWEI) and Magneto-acousto-electrical tomography (MAET) to measure soft tissue's elasticity and conductivity simultaneously. A dual-modal imaging system based on a linear array transducer is built, and the imaging performances of MAET and SWEI were respectively evaluated by phantoms experiment and \textit{in vitro} experiment. Conductivity phantom experiments show that the MAET in this dual-modal system can image conductivity gradient as low as 0.4 S/m. The phantom experiments show that the reconstructed 2-D elasticity maps of the phantoms with inclusions with a diameter larger than 5 mm are relatively accurate. \textit{In vitro} experiments show that the elasticity parameter can significantly distinguish the changes in tissue before and after heating. This study first proposes a method that can simultaneously obtain tissue elasticity and electrical conductivity to the best of our knowledge. Although this paper just carried out the proof of concept experiments of the new method, it demonstrates great potential for disease diagnosis in the future.
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Measuring and Modelling Nonlinear Elasticity of Ex Vivo Mouse Muscles. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:5579232. [PMID: 34840699 PMCID: PMC8612782 DOI: 10.1155/2021/5579232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 10/28/2021] [Indexed: 11/17/2022]
Abstract
Elastography is a noninvasive imaging technique that provides information on soft tissue stiffness. Young's modulus is typically used to characterize soft tissues' response to the applied force, as soft tissues are often considered linear elastic, isotropic, and quasi-incompressible materials. This approximation is reasonable for small strains, but soft tissues undergo large deformations also for small values of force and exhibit nonlinear elastic behavior. Outside the linear regime, the elastic modulus is dependent on the strain level and is different for any kind of tissue. The aim of this study was to characterize, ex vivo, the mechanical response of two different mice muscles to an external force. A system for transverse force-controlled uniaxial compression enabled obtaining the stress-strain (σ-ε) curve of the samples. The strain-dependent Young's modulus (SYM) model was adopted to reproduce muscle compression behavior and to predict the elastic modulus for large deformations. After that, a recursive linear model was employed to identify the initial linear region of the σ-ε curve. Results showed that both muscle types exhibited a strain hardening effect and that the SYM model provided good fitting of the entire σ-ε curves. The application of the recursive linear model allowed capturing the initial linear region in which the approximation of these tissues as linear elastic materials is reasonable. The residual analysis displayed that even if the SYM model better summarizes the muscle behavior on the entire region, the linear model is more precise when considering only the initial part of the σ-ε curve.
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14
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Rosen DP, Larson NB, Alizad A, Fatemi M. Non-invasive measurement of the internal pressure of a pressurized biological compartment using Lamb waves. IEEE Trans Biomed Eng 2021; 69:1860-1869. [PMID: 34807817 DOI: 10.1109/tbme.2021.3129652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this study, we propose a mechanical analysis for estimating the internal pressure of a finitely deformed spherical compartment from Lamb wave measurements. The proposed analysis produces a dispersion relation associating Lamb wave speed with pressure using limited material parameters (only a strain stiffening term). The analysis was validated on ultrasound bladder vibrometry (UBV) experiments collected from 9 ex vivo porcine bladders before and after formalin cross-linking. Estimated pressures were compared with pressures measured directly by a pressure transducer. The proposed analysis proved broadly effective at estimating pressure from UBV based Lamb wave without calibration as demonstrated by the observed concordance between estimated and measured pressures (Lins CCC = 0.82 (0.66-0.91). Theoretical limitations and potential refinements to improve the accuracy and generality of the approach are discussed.
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Zemzemi C, Catheline S, Turquier F. Shear wave elastography biases in abdominal wall layers characterization. Phys Med Biol 2021; 66. [PMID: 34560674 DOI: 10.1088/1361-6560/ac29cd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 09/24/2021] [Indexed: 11/12/2022]
Abstract
Ventral incisional hernia repair is one of the most common surgical procedures. The characterization of the abdominal wall layer mechanical properties is the first step towards personalized treatment. This study investigates the capability of elastography to assess these properties using anin vivoandin vitromodel of abdominal wall layers. Two experiment approaches are considered: shear wave elastography imaging and guided wave dispersion characterization, where the latter is used as a reference. Results show measurement biases in the shear wave elastography approach in such a layer structure configuration. Methods to overcome these biases are suggested to improve and to correct the elastography approach for abdominal wall layers and similar anatomical structures.
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Affiliation(s)
- C Zemzemi
- LabTAU, INSERM, Centre Léon Bérard, Université Lyon 1, Univ-Lyon, F-69003, Lyon, France
| | - S Catheline
- LabTAU, INSERM, Centre Léon Bérard, Université Lyon 1, Univ-Lyon, F-69003, Lyon, France
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16
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Urban MW, Rule AD, Atwell TD, Chen S. Novel Uses of Ultrasound to Assess Kidney Mechanical Properties. KIDNEY360 2021; 2:1531-1539. [PMID: 34939037 PMCID: PMC8691758 DOI: 10.34067/kid.0002942021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ultrasound is a key imaging tool for evaluating the kidney. Over the last two decades, methods to measure the mechanical properties of soft tissues have been developed and used in clinical practice, although use in the kidney has not been as widespread as for other applications. The mechanical properties of the kidney are determined by the structure and composition of the renal parenchyma and perfusion characteristics. Because pathologic processes change these factors, the mechanical properties change and can be used for diagnostic purposes and for monitoring treatment or disease progression. Ultrasound-based elastography methods for evaluating the mechanical properties of the kidney use focused ultrasound beams to perturb the kidney and then high frame-rate ultrasound methods are used to measure the resulting motion. The motion is analyzed to estimate the mechanical properties. This review will describe the principles of these methods and discuss several seminal studies related to characterizing the kidney. Additionally, an overview of the clinical use of elastography methods in native and kidney allografts will be provided. Perspectives on future developments and uses of elastography technology along with other complementary ultrasound imaging modalities will be provided.
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Affiliation(s)
| | - Andrew D. Rule
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | | | - Shigao Chen
- Department of Radiology, Mayo Clinic, Rochester, Minnesota
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Tarapure S, Tubaki BR, Khot S. Elastographic liver evaluation of Katukyadi churna in the management of Non-Alcoholic Steatohepatitis (NASH) - A single arm clinical trial. J Ayurveda Integr Med 2021; 12:136-142. [PMID: 33579578 PMCID: PMC8039359 DOI: 10.1016/j.jaim.2020.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 02/07/2023] Open
Abstract
Non Alcoholic Steatohepatitis (NASH) is the most severe histological form of non-alcoholic fatty liver disease (NAFLD). It progress to cirrhosis in 20% population and 40% will have death due to liver pathology. Still consensus on pharmacotherapy is yet to be evolved and till date there is no US FDA approved drug for NASH. Ayurveda formulation Katukyadi churna is explored in the possible management of NASH. Study is a single arm with pre and post test design. Sonologically diagnosed patients of fatty liver (n = 30) were screened. 11 patients meeting elastoghraphic criteria (6.4-11.7 kPa) were enrolled in the study. K. churna was administered in the dose of 6 g twice a day with water at the middle of the meal for a period of 6 months. Subjective parameters were Aruchi (Anorexia), Agnimandhya (loss of appetite), Ajeerna (indigestion), Gouravata. Follow up assessments were done on every 30th day. Study showed that K. churna produced significant improvement in various parameters. Significant decrease in weight, (p < 0.001), BMI (p < 0.001), Elastography (p = 0.001), total bilirubin (p = 0.02), Alanine Aminotransferase (ALT) (p < 0.001), Aspartate Aminotransferase (AST) (p = 0.001), Albumin (p = 0.04), Triglycerides (p = 0.005) were observed. Subjective symptoms like Ajeerna (p = 0.002), Agnimandhya (p = 0.004), Arochaka (p = 0.001), Gouvravata (p = 0.002) showed significant improvement. K. churna showed clinical significance in terms of improvement from pathological ranges to normative ranges in elastography, total bilirubin, AST, Albumin. K. churna reduced weight, BMI, hardness and stiffness of the liver, liver function derangements, triglycerides and improved other subjective clinical parameters. Drug has promising results in NASH and warrants further studies.
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Affiliation(s)
- Shruti Tarapure
- Department of Kayachikitsa, Seth Govindji Raoji Ayurved Medical College, Solapur, Maharashtra, 413001, India
| | - Basavaraj R Tubaki
- Department of Kayachikitsa, Shri BMK Ayurveda Mahavidyalaya, A Constituent Unit of KLE Academy of Higher Education & Research, Belagavi, Karnataka, India.
| | - Siddhi Khot
- Department of Kayachikitsa, Shri BMK Ayurveda Mahavidyalaya, A Constituent Unit of KLE Academy of Higher Education & Research, Belagavi, Karnataka, India
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18
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Spleen elastography in patients with Systemic sclerosis. Rheumatol Int 2021; 41:633-641. [PMID: 33495915 DOI: 10.1007/s00296-020-04772-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 12/12/2020] [Indexed: 12/17/2022]
Abstract
Systemic sclerosis (SSc) is an autoimmune inflammatory connective tissue disease. It is characterized by varying degrees of fibrosis of the skin and internal organs. Tissue fibrosis is the final phase of a complex biological process of immune activation and vascular damage. The spleen is one of the organs thought to be involved in a systemic fibrosing process. Yet, there is a lack of research that provides evidence about splenic involvement in patients with SSc through objective instrumental techniques. Ultrasound elastography is a modern method which detects changes in the stiffness and elasticity of different organs. To assess the elasticity and stiffness of the spleen in healthy subjects and patients with SSc, the study included 34 patients with SSc and 35 healthy volunteers. Point SWE spleen elastography was performed on all participants in the two study groups through an Esaote MyLab 9 eXP with a C1-8 iQ appleprobe transducer. The mean age in the SSc patient group was 47.35 ± 11.48 years vs. 46.20 ± 14.55 years in the healthy controls, with no significant age difference, p = 0.717. The mean Body Mass Index (BMI) in the SSc patient group was 22.42 ± 2.12 kg/m2 vs. 24.23 ± 4.29 kg/m2 in the healthy control group with no significant difference, p = 0.410. Among the SSc patients, 18(53%) were with dcSSc and 16 (47%) with lcSSc. The mean disease duration was 59 ± 28 months, ranging between 18 and 118 months. Spleen stiffness median was significantly higher in the SSc patient group (3.19 m/s) in comparison with the healthy controls (2.40 m/s), p < 0.001. Spleen size was normally distributed and did not differ significantly between the SSc patients (105.84 ± 7.87 mm) and the healthy controls (104.16 ± 8.99 mm), p = 0.410. A significantly higher mean of spleen stiffness was observed in the dcSSc patients (3.38 ± 0.20 m/s) in comparison with the lcSSc group (2.81 ± 0.38 m/s), p < 0.001. Spleen size did not show a significant association with the type of SSc. Spleen size in the dcSSc subgroup had a mean value of 103.45 ± 5.56 mm vs. 108.51 ± 9.30 in the lcSSc subgroup, p = 0.071. pSWE is an objective, reliable, and easy-to-implement method for detecting early fibrous changes in the spleen in patients with SSc. A good approach in patients with SSc could be the search for similar processes in other internal organs, such as the liver and thyroid gland.
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Comparison of nasal airway obstruction with sonoelastography and nose obstruction symptom evaluation scores in children with allergic rhinitis. Turk Arch Pediatr 2021; 56:27-31. [PMID: 34013226 DOI: 10.14744/turkpediatriars.2020.87894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 05/18/2020] [Indexed: 11/20/2022]
Abstract
Objective Nasal airway obstruction caused by inferior turbinate hypertrophy is the most troublesome symptom for patients with allergic rhinitis. The aim of this study was to determine any correlation between different nasal obstruction measurements in children with allergic rhinitis. Material and Methods Nasal airway obstruction was assessed with Sonoelastography, Turkish version of the Nose Obstruction Symptom Evaluation scale, Rhinoconjunctivitis Total Symptom Score and visual analog scale methods in children with allergic rhinitis and the results were compared with a healthy control group. Results Evaluation was made of a total of 68 patients (40 boys and 28 girls [male: female ratio, 1.42]) with a mean age of 13.35±3.35 (range, 7-18) years. The Rhinoconjunctivitis Total Symptom Score, visual analog scale, and Turkish version of the Nose Obstruction Symptom Evaluation scale scores were significantly higher in the AR group than in the control group (p=0.001, p=0.001, p=0.001, respectively). The sonoelastography scores were significantly higher in the AR group than in the control group (p=0.001). Although a positive significant correlation was determined between Rhinoconjunctivitis Total Symptom Score, visual analog scale, and Turkish version of the Nose Obstruction Symptom Evaluation scale scores in terms of AR severity, no relationship was found with the sonoelastography scores (p=0.022, p=0.009, p=0.001, and p=0.0751, respectively). Conclusion The Turkish version of the Nose Obstruction Symptom Evaluation scale and sonoelastography can be used to evaluate nasal obstruction due to inferior turbinate hypertrophy in children with allergic rhinitis.
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Toniolo I, Fontanella CG, Foletto M, Carniel EL. Biomechanical Investigation of the Stomach Following Different Bariatric Surgery Approaches. Bioengineering (Basel) 2020; 7:bioengineering7040159. [PMID: 33317122 PMCID: PMC7764040 DOI: 10.3390/bioengineering7040159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/02/2020] [Accepted: 12/07/2020] [Indexed: 12/15/2022] Open
Abstract
Background: The stomach is a hollow organ of the gastrointestinal tract, on which bariatric surgery (BS) is performed for the treatment of obesity. Even though BS is the most effective treatment for severe obesity, drawbacks and complications are still present because the intervention design is largely based on the surgeon’s expertise and intraoperative decisions. Bioengineering methods can be exploited to develop computational tools for more rational presurgical design and planning of the intervention. Methods: A computational mechanical model of the stomach was developed, considering the actual complexity of the biological structure, as the nonhomogeneous and multilayered configuration of the gastric wall. Mechanical behavior was characterized by means of an anisotropic visco-hyperelastic constitutive formulation of fiber-reinforced conformation, nonlinear elastic response, and time-dependent behavior, which assume the typical features of gastric wall mechanics. Model applications allowed for an analysis of the influence of BS techniques on stomach mechanical functionality through different computational analyses. Results: Computational results showed that laparoscopic sleeve gastrectomy and endoscopic sleeve gastroplasty drastically alter stomach capacity and stiffness, while laparoscopic adjustable gastric banding modestly affects stomach stiffness and capacity. Moreover, the mean elongation strain values, which are correlated to the mechanical stimulation of gastric receptors, were elevated in laparoscopic adjustable gastric banding compared to other procedures. Conclusions: The investigation of stomach mechanical response through computational models provides information on different topics such as stomach capacity and stiffness and the mechanical stimulation of gastric receptors, which interact with the brain to control satiety. These data can provide reliable support to surgeons in the presurgical decision-making process.
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Affiliation(s)
- Ilaria Toniolo
- Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padova, Italy; (I.T.); (E.L.C.)
| | - Chiara Giulia Fontanella
- Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padova, Italy; (I.T.); (E.L.C.)
- Centre for Mechanics of Biological Materials, University of Padova, Via F. Marzolo 9, 35131 Padova, Italy;
- Correspondence: ; Tel.: +39-049-8276754
| | - Mirto Foletto
- Centre for Mechanics of Biological Materials, University of Padova, Via F. Marzolo 9, 35131 Padova, Italy;
- IFSO Bariatric Center of Excellence, Padova University Hospital, Via Ospedale Civile, 35121 Padova, Italy
| | - Emanuele Luigi Carniel
- Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padova, Italy; (I.T.); (E.L.C.)
- Centre for Mechanics of Biological Materials, University of Padova, Via F. Marzolo 9, 35131 Padova, Italy;
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Li GY, Gower AL, Destrade M. An ultrasonic method to measure stress without calibration: The angled shear wave method. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 148:3963. [PMID: 33379903 DOI: 10.1121/10.0002959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Measuring stress levels in loaded structures is crucial to assess and monitor structure health and to predict the length of remaining structural life. Many ultrasonic methods are able to accurately predict in-plane stresses inside a controlled laboratory environment but struggle to be robust outside, in a real-world setting. That is because these methods rely either on knowing beforehand the material constants (which are difficult to acquire) or require significant calibration for each specimen. This paper presents an ultrasonic method to evaluate the in-plane stress in situ directly, without knowing any material constants. The method is simple in principle, as it only requires measuring the speed of two angled shear waves. It is based on a formula that is exact for incompressible solids, such as soft gels or tissues, and is approximately true for compressible "hard" solids, such as steel and other metals. The formula is validated by finite element simulations, showing that it displays excellent accuracy, with a small error on the order of 1%.
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Affiliation(s)
- Guo-Yang Li
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Artur L Gower
- Department of Mechanical Engineering, University of Sheffield, Sheffield, United Kingdom
| | - Michel Destrade
- School of Mathematics, Statistics and Applied Mathematics, NUI Galway, Galway, Ireland
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22
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Forte AJ, Huayllani MT, Boczar D, Cinotto G, Ciudad P, Manrique OJ, Lu X, McLaughlin SA. The basics of ultrasound elastography for diagnosis, assessment, and staging breast cancer-related lymphedema: a systematic review of the literature. Gland Surg 2020; 9:589-595. [PMID: 32420294 DOI: 10.21037/gs.2020.02.08] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Breast cancer-related lymphedema (BCRL) incidence has been increasing overtime. Currently, there is not a preferred imaging tool for diagnosis, staging, and assessment of the disease. We aim to review the use of ultrasound elastography (UE) in BCRL patients. A systematic review was performed by querying PubMed, EMBASE, Ovid Healthstar, and Ovid Medline databases for studies that evaluated the use of UE in BCRL. The keywords "elastography" AND "lymphedema" in titles and abstracts were used for the search. The search retrieved 12, 12, 5 and 6 articles in each database, respectively. From these, only 4 met the inclusion criteria. UE methods included two-dimensional strain imaging, shear wave elastography (SWE), and global UE. Two of the studies evaluated the use of UE in the assessment of BCRL, while only 1 considered its use for diagnosis and staging. Based on our systematic review, UE appears to be a great tool in the assessment of BCRL to differentiate affected from non-affected arms.
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Affiliation(s)
- Antonio J Forte
- Division of Plastic Surgery and Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Jacksonville, FL, USA
| | - Maria T Huayllani
- Division of Plastic Surgery and Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Jacksonville, FL, USA
| | - Daniel Boczar
- Division of Plastic Surgery and Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Jacksonville, FL, USA
| | - Gabriela Cinotto
- Division of Plastic Surgery and Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Jacksonville, FL, USA
| | - Pedro Ciudad
- Department of Plastic, Reconstructive and Burn Surgery, Arzobispo Loayza National Hospital, Lima, Peru
| | | | - Xiaona Lu
- Division of Plastic and Reconstructive Surgery, Yale School of Medicine, New Haven, CT, USA
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Knight AE, Lipman SL, Ketsiri T, Hobson-Webb LD, Nightingale KR. On the Challenges Associated with Obtaining Reproducible Measurements Using SWEI in the Median Nerve. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:1092-1104. [PMID: 32057471 PMCID: PMC7419061 DOI: 10.1016/j.ultrasmedbio.2019.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/25/2019] [Accepted: 12/29/2019] [Indexed: 05/03/2023]
Abstract
This work discusses challenges we have encountered in acquiring reproducible measurements of shear wave speed (SWS) in the median nerve and suggests methods for improving reproducibility. First, procedural acquisition challenges are described, including nerve echogenicity, transducer pressure and transmit focal depth. Second, we present an iterative, radon sum-based algorithm that was developed specifically for measuring the SWS in median nerves. SWSs were measured using single track location shear wave elasticity imaging (SWEI) in the median nerves of six healthy volunteers and six patients diagnosed with carpal tunnel syndrome. Unsuccessful measurements were associated with several challenges including reverberation artifacts, low signal-to-noise ratio and temporal window limitations for tracking the velocity wave. To address these challenges, an iterative convergence algorithm was implemented to identify an appropriate temporal processing window that removed the reverberation artifacts while preserving shear wave signals. Algorithmically, it was important to consider the lateral regression kernel size and position and the temporal window. Procedurally, both nerve echogenicity and transducer compression were determined to impact the measured SWS. Shear waves were successfully measured in the median nerve proximal to the carpal tunnel, but SWEI measurements were significantly compromised within the carpal tunnel itself. The velocity-based SWSs were statistically significantly higher than the displacement SWSs (p < 0.0001), demonstrating for the first time dispersion in the median nerve in vivo using SWEI.
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Affiliation(s)
- Anna E Knight
- Duke Biomedical Engineering, Duke University, Durham, NC.
| | | | | | - Lisa D Hobson-Webb
- Duke Department of Neurology/Neuromuscular Division, Duke University, Durham, NC
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Costa G, Gentile F. A nanomechanical model enables comprehensive characterization of biological tissues in ultrasound imaging. Biomed Phys Eng Express 2020; 6:035026. [PMID: 33438671 DOI: 10.1088/2057-1976/ab8740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Sonography, elastography, sonoelastography are ultrasound imaging techniques commonly used in the clinical practice for the diagnosis of many pathological conditions. These highly reliable, non-invasive methods use high frequency, elastic pressure waves (ultrasounds) to interrogate the internal structure of biological tissues and organs, and the continuum mechanics hypothesis to reconstruct, from the output of the system, the biophysical characteristics of the samples. Nevertheless, continuum mechanics disregards the discrete nature of tissues and organs, resulting in an inability for the model to describe some important tissue biophysical characteristics such as the cell size and their spatial layout. Here, we used the theory of doublet mechanics - a discrete nano-mechanical field theory - to model the propagation of ultrasounds in a multilayered biological tissue. We found that the output of the model exhibits a very high sensitivity to the macro and micro characteristics of the tissue, including cell size. We used results from the model to correlate the internal structure of the samples to the reflection coefficient, i.e. the continuum level response of the system. This model, and its more sophisticated evolutions that will be developed over time, can complement traditional ultrasound imaging, and provide ways to analyze non-invasively living tissues with a resolution inaccessible to conventional techniques of analysis, including positron emission tomography, computer tomography, and magnetic resonance.
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Affiliation(s)
- G Costa
- Institute for Microelectronics and Microsystems, National Research Council (CNR), 80131 Naples, Italy
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25
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Schrier VJMM, Lin J, Gregory A, Thoreson AR, Alizad A, Amadio PC, Fatemi M. Shear wave elastography of the median nerve: A mechanical study. Muscle Nerve 2020; 61:826-833. [PMID: 32170959 DOI: 10.1002/mus.26863] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 02/03/2020] [Accepted: 03/10/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Shear wave elastography (SWE) shows promise in peripheral neuropathy evaluation but has potential limitations due to tissue size and heterogeneity. We tested SWE sensitivity to elasticity change and the effect of probe position in a median nerve cadaver model. METHODS Ten specimens were used to measure median nerve elasticity under increasing loads using SWE and indentation. Measurements were compared using repeated-measures analysis of variance. RESULTS Indentation and SWE-based longitudinal nerve elasticity increased with tensile loading (P < .01), showing a similar relationship. Acquisition in a transverse plane showed lower values compared with longitudinal measurements, mostly under higher loads (P = .03), as did postdissection elasticity (P = .02). Elasticity did not change when measured proximal to the carpal tunnel. CONCLUSIONS Longitudinal SWE is sensitive to changes in median nerve elasticity. Measuring elasticity of peripheral nerves noninvasively could elucidate intra-neural pathology related to compression neuropathies, and proof to be of added value as a diagnostic or prognostic tool.
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Affiliation(s)
- Verena J M M Schrier
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Mayo Clinic Minnesota, Rochester, Minnesota
| | - Jason Lin
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Mayo Clinic Minnesota, Rochester, Minnesota
| | - Adriana Gregory
- Department of Radiology, Mayo Clinic Minnesota, Rochester, Minnesota
| | - Andrew R Thoreson
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Mayo Clinic Minnesota, Rochester, Minnesota
| | - Azra Alizad
- Department of Radiology, Mayo Clinic Minnesota, Rochester, Minnesota
| | - Peter C Amadio
- Biomechanics Laboratory and Tendon and Soft Tissue Biology Laboratory, Mayo Clinic Minnesota, Rochester, Minnesota
| | - Mostafa Fatemi
- Department of Physiology and Biomedical Engineering, Mayo Clinic Minnesota, Rochester, Minnesota
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Nabavizadeh A, Payen T, Iuga AC, Sagalovskiy IR, Desrouilleres D, Saharkhiz N, Palermo CF, Sastra SA, Oberstein PE, Rosario V, Kluger MD, Schrope BA, Chabot JA, Olive KP, Konofagou EE. Noninvasive Young's modulus visualization of fibrosis progression and delineation of pancreatic ductal adenocarcinoma (PDAC) tumors using Harmonic Motion Elastography (HME) in vivo. Theranostics 2020; 10:4614-4626. [PMID: 32292518 PMCID: PMC7150482 DOI: 10.7150/thno.37965] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023] Open
Abstract
Background and aims: Poor specificity and predictive values of current cross-sectional radiological imaging methods in evaluation of pancreatic adenocarcinoma (PDAC) limit the clinical capability to accurately stage the tumor pre-operatively and provide optimal surgical treatment and improve patient outcomes. Methods: In this study, we applied Harmonic Motion Elastography (HME), a quantitative ultrasound-based imaging method to calculate Young's modulus (YM) in PDAC mouse models (n = 30) and human pancreatic resection specimens of PDAC (n=32). We compared the YM to the collagen assessment by Picrosirius red (PSR) stain on corresponding histologic sections. Results: HME is capable of differentiating between different levels of fibrosis in transgenic mice. In mice without pancreatic fibrosis, the measured YM was 4.2 ± 1.3 kPa, in fibrotic murine pancreata, YM was 5.5 ± 2.0 kPa and in murine PDAC tumors, YM was 11.3 ± 1.7 kPa. The corresponding PSR values were 2.0 ± 0.8 %, 9.8 ± 3.4 %, and 13.2 ± 1.2%, respectively. In addition, three regions within each human surgical PDAC specimen were assessed: tumor, which had both the highest Young's modulus (YM > 40 kPa) and collagen density (PSR > 40 %); non-neoplastic adjacent pancreas, which had the lowest Young's modulus (YM < 15 kPa) and collagen density (PSR < 10%) and a transitional peri-lesional region between the tumor and non-neoplastic pancreas with an intermediate value of measured Young's modulus (15 kPa < YM < 40 kPa) and collagen density (15% < PSR < 35 %). Conclusion: In conclusion, a non-invasive, quantitative imaging tool for detecting, staging and delineating PDAC tumor margins based on the change in collagen density was developed.
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Abstract
A rising wave of technologies and instruments are enabling more labs and clinics to make a variety of measurements related to tissue viscoelastic properties. These instruments include elastography imaging scanners, rheological shear viscometers, and a variety of calibrated stress-strain analyzers. From these many sources of disparate data, a common step in analyzing results is to fit the measurements of tissue response to some viscoelastic model. In the best scenario, this places the measurements within a theoretical framework and enables meaningful comparisons of the parameters against other types of tissues. However, there is a large set of established rheological models, even within the class of linear, causal, viscoelastic solid models, so which of these should be chosen? Is it simply a matter of best fit to a minimum mean squared error of the model to several data points? We argue that the long history of biomechanics, including the concept of the extended relaxation spectrum, along with data collected from viscoelastic soft tissues over an extended range of times and frequencies, and the theoretical framework of multiple relaxation models which model the multi-scale nature of physical tissues, all lead to the conclusion that fractional derivative models represent the most succinct and meaningful models of soft tissue viscoelastic behavior. These arguments are presented with the goal of clarifying some distinctions between, and consequences of, some of the most commonly used models, and with the longer term goal of reaching a consensus among different sub-fields in acoustics, biomechanics, and elastography that have common interests in comparing tissue measurements.
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Affiliation(s)
- K J Parker
- Department of Electrical and Computer Engineering, University of Rochester, 724 Computer Studies Building, Box 270231, Rochester, NY 14627, United States of America. Author to whom any correspondence should be addressed
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Evaluation of the optic nerve using strain and shear-wave elastography in pre-eclampsia. Clin Radiol 2019; 74:813.e1-813.e9. [DOI: 10.1016/j.crad.2019.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/11/2019] [Indexed: 01/09/2023]
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Xu HX, Yan K, Liu BJ, Liu WY, Tang LN, Zhou Q, Wu JY, Xue ES, Shen B, Tang Q, Chen Q, Xue HY, Li YJ, Guo J, Wang B, Li F, Yan CY, Li QS, Wang YQ, Zhang W, Wu CJ, Yu WH, Zhou SJ. Guidelines and recommendations on the clinical use of shear wave elastography for evaluating thyroid nodule1. Clin Hemorheol Microcirc 2019; 72:39-60. [PMID: 30320562 DOI: 10.3233/ch-180452] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Hui-Xiong Xu
- Department of Medical Ultrasound, Shanghai Tenth People’s Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine, Shanghai, China
- Thyroid Institute, Tongji University School of Medicine, Shanghai, China
- Shanghai Center for Thyroid Diseases, Shanghai, China
| | - Kun Yan
- Department of Ultrasound, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Peking University Cancer Hospital & Institute, Beijing, China
| | - Bo-Ji Liu
- Department of Medical Ultrasound, Shanghai Tenth People’s Hospital, Ultrasound Research and Education Institute, Tongji University School of Medicine, Shanghai, China
- Thyroid Institute, Tongji University School of Medicine, Shanghai, China
- Shanghai Center for Thyroid Diseases, Shanghai, China
| | - Wen-Ying Liu
- Department of Ultrasound, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Peking University Cancer Hospital & Institute, Beijing, China
| | - Li-Na Tang
- Department of Ultrasound, Fujian Cancer Hospital & Fujian Medical University Cancer Hospital, Fuzhou, China
| | - Qi Zhou
- Department of Ultrasound, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Jin-Yu Wu
- Department of Ultrasound, Harbin First Hospital, Harbin, China
| | - En-Sheng Xue
- Department of Ultrasound, Union Hospital, Fujian Medical University, Fuzhou, China
| | - Bin Shen
- Department of Ultrasound, People’s Hospital of Fenghua, Fenghua, China
| | - Qing Tang
- Department of Ultrasound, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qin Chen
- Department of Ultrasound, Sichuan Provincial People’s Hospital, Chengdu, China
| | - Hong-Yuan Xue
- Department of Ultrasound, Hebei General Hospital, Shijiazhuang, China
| | - Ying-Jia Li
- Department of Ultrasound, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jun Guo
- Department of Ultrasound, Peking University Aerospace School of Clinical Medicine, Beijing, China
| | - Bin Wang
- Department of Ultrasound, Peking University First Hospital, Beijing, China
| | - Fang Li
- Department of Ultrasound, Chongqing Cancer Hospital, Chongqing, China
| | - Chun-Yang Yan
- Department of Ultrasound, Seventh People’s Hospital of Ningbo, Ningbo, China
| | - Quan-Shui Li
- Department of Ultrasound, Luohu Hospital Group Affiliated to Shenzhen University, Shenzhen, China
| | - Yan-Qing Wang
- Department of Ultrasound, Zhengzhou People’s Hospital, Zhengzhou, China
| | - Wei Zhang
- Department of Ultrasound, The Third Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chang-Jun Wu
- Department of Ultrasound, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Wen-Hui Yu
- Department of Ultrasound, Wuchang Hospital of Hubei Province, Wuhan, China
| | - Su-Jin Zhou
- Department of Ultrasound, Guangdong Second Provincial General Hospital, Guangzhou, China
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van der Vaart K, Sinhuber M, Reynolds AM, Ouellette NT. Mechanical spectroscopy of insect swarms. SCIENCE ADVANCES 2019; 5:eaaw9305. [PMID: 31501772 PMCID: PMC6719412 DOI: 10.1126/sciadv.aaw9305] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/03/2019] [Indexed: 05/02/2023]
Abstract
Social animals routinely form groups, which are thought to display emergent, collective behavior. This hypothesis suggests that animal groups should have properties at the group scale that are not directly linked to the individuals, much as bulk materials have properties distinct from those of their constituent atoms. Materials are often probed by measuring their response to controlled perturbations, but these experiments are difficult to conduct on animal groups, particularly in the wild. Here, we show that laboratory midge swarms have emergent continuum mechanical properties, displaying a collective viscoelastic response to applied oscillatory visual stimuli that allows us to extract storage and loss moduli for the swarm. We find that the swarms strongly damp perturbations, both viscously and inertially. Thus, unlike bird flocks, which appear to use collective behavior to promote lossless information flow through the group, our results suggest that midge swarms use it to stabilize themselves against environmental perturbations.
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Affiliation(s)
- Kasper van der Vaart
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
| | - Michael Sinhuber
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
| | | | - Nicholas T. Ouellette
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
- Corresponding author.
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31
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Li GY, Zhang ZY, Qian J, Zheng Y, Liu W, Wu H, Cao Y. Mechanical characterization of functionally graded soft materials with ultrasound elastography. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180075. [PMID: 30879421 PMCID: PMC6452040 DOI: 10.1098/rsta.2018.0075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Functionally graded soft materials (FGSMs) with microstructures and mechanical properties exhibiting gradients across a spatial volume to satisfy specific functions have received interests in recent years. How to characterize the mechanical properties of these FGSMs in vivo/in situ and/or in a non-destructive manner is a great challenge. This paper investigates the use of ultrasound elastography in the mechanical characterization of FGSMs. An efficient finite-element model was built to calculate the dispersion relation for surface waves in FGSMs. For FGSMs with large elastic gradients, the measured dispersion relation can be used to identify mechanical parameters. In the case where the elastic gradient is smaller than a certain critical value calculated here, our analysis on transient wave motion in FGSMs shows that the group velocities measured at different depths can infer the local mechanical properties. Experiments have been performed on polyvinyl alcohol (PVA) cryogel to demonstrate the usefulness of the method. Our analysis and the results may not only find broad applications in mechanical characterization of FGSMs but also facilitate the use of shear wave elastography in clinics because many diseases change the local elastic properties of soft tissues and lead to different material gradients. This article is part of the theme issue 'Rivlin's legacy in continuum mechanics and applied mathematics'.
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Affiliation(s)
- Guo-Yang Li
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Zhao-Yi Zhang
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jialin Qian
- Beijing Center for Physical and Chemical Analysis, Beijing 100089, People's Republic of China
- Beijing Engineering Technique Research Center for Gene Sequencing & Function Analysis, Beijing 100094, People's Republic of China
| | - Yang Zheng
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wenli Liu
- Beijing Center for Physical and Chemical Analysis, Beijing 100089, People's Republic of China
- Beijing Engineering Technique Research Center for Gene Sequencing & Function Analysis, Beijing 100094, People's Republic of China
| | - Huijuan Wu
- Beijing Center for Physical and Chemical Analysis, Beijing 100089, People's Republic of China
- Beijing Engineering Technique Research Center for Gene Sequencing & Function Analysis, Beijing 100094, People's Republic of China
| | - Yanping Cao
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing 100084, People's Republic of China
- e-mail:
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32
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Park DW, Lee YJ, Chang W, Park JH, Lee KH, Kim YH, Kang NK, Chung JW, Jang HY, Ahn S, Kim H, Jeong SH, Kim JW, Jang ES. Diagnostic performance of a point shear wave elastography (pSWE) for hepatic fibrosis in patients with autoimmune liver disease. PLoS One 2019; 14:e0212771. [PMID: 30856201 PMCID: PMC6411150 DOI: 10.1371/journal.pone.0212771] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 02/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND & AIMS Elastography point quantification is a convenient method for measuring liver stiffness. It can be performed simultaneously with conventional ultrasonography. This study aimed to evaluate its diagnostic performance for assessing hepatic fibrosis in patients with autoimmune liver disease (AILD), including autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). METHODS The diagnostic performance of elastography point quantification (ElastPQ) was evaluated and compared with that of serum fibrosis markers, including the aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4), using the receiver operating characteristics analysis with histologic evaluation as the reference standard. RESULTS In 49 AIH patients, sensitivity and specificity of ElastPQ were 93.6% and 44.4%, respectively, for significant fibrosis (≥ F2, cutoff 4.47 kPa), and 63.6% and 86.8% for cirrhosis (F4, cutoff 9.28 kPa). In 41 PBC patients, they were 81.8% and 73.3%, respectively, for significant fibrosis (≥ F2, cutoff 5.56 kPa), and 100% and 81.6%, respectively, for advanced fibrosis (≥ F3, cutoff 6.04 kPa). The areas under the receiver operating characteristic curves of ElastPQ for significant fibrosis (0.77, 95% CI 0.67-0.86) and cirrhosis (0.81, 95% CI 0.65-0.96) were higher than those of APRI and FIB-4 in AILD patients. According to the multivariable analysis, histological activity, steatosis, and body max index (BMI) were not significant factors that influenced the result of ElastPQ. CONCLUSIONS ElastPQ exhibited better diagnostic performance-without the influence of confounding factors-for assessing hepatic fibrosis in AILD patients than serum fibrosis markers.
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Affiliation(s)
- Dong Won Park
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Yoon Jin Lee
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Won Chang
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Ji Hoon Park
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Kyoung Ho Lee
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Young Hoon Kim
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Nam Kyu Kang
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Jung Wha Chung
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Hee Yoon Jang
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Soomin Ahn
- Department of Pathology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Haeryoung Kim
- Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sook-Hyang Jeong
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Jin-Wook Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Eun Sun Jang
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
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33
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Li GY, Zheng Y, Jiang YX, Zhang Z, Cao Y. Guided wave elastography of layered soft tissues. Acta Biomater 2019; 84:293-304. [PMID: 30528611 DOI: 10.1016/j.actbio.2018.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/28/2018] [Accepted: 12/04/2018] [Indexed: 12/17/2022]
Abstract
In vivo mechanical characterization of soft biological tissues has broad applications ranging from disease diagnosis to tissue engineering. Shear wave elastography based on the bulk wave theory has been widely used to measure the mechanical properties of soft tissues. Given that most soft tissues basically have layered structures, the dispersive feature of elastic waves should be considered when the thickness of the interested layer is comparable to or smaller than the wavelength. Bearing this fundamental issue in mind, we propose an ultrasound-based guided wave elastography (GWE) method to characterize the mechanical properties of layered soft tissues. The dispersion relations of guided waves in layered structures were derived first, and its explicit expression was achieved. An inverse approach based on the dispersion relation to characterize the mechanical properties of layered soft tissues was then established. Both finite element analysis (FEA) and phantom experiments were carried out to validate the new method. In vivo experiments on forearm skin demonstrate the usefulness of the present method in characterizing layered soft tissues. STATEMENT OF SIGNIFICANCE: Layered soft tissues and artificial soft materials are ubiquitous in both nature and engineering. Imaging their in vivo/in situ mechanical properties finds important applications and remains a great challenge to date. Here, we propose an ultrasound-based guided wave elastography method to in vivo/in situ characterize the elastic properties of layered soft materials. We validate the method via finite element analysis and phantom experiments and further demonstrate its usefulness in practice by performing in vivo measurements on forearm skins. Given that the dispersive feature of elastic waves in layered soft media is considered in our method, it provides the opportunity to assess the intrinsic elastic properties of an individual layer in a non-destructive manner as shown in our experiments.
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Affiliation(s)
- Guo-Yang Li
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, PR China
| | - Yang Zheng
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, PR China
| | - Yu-Xuan Jiang
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, PR China
| | - Zhaoyi Zhang
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, PR China
| | - Yanping Cao
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, PR China.
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Ang M, Wong CW, Hoang QV, Cheung GCM, Lee SY, Chia A, Saw SM, Ohno-Matsui K, Schmetterer L. Imaging in myopia: potential biomarkers, current challenges and future developments. Br J Ophthalmol 2019; 103:855-862. [DOI: 10.1136/bjophthalmol-2018-312866] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 12/20/2018] [Accepted: 12/22/2018] [Indexed: 12/21/2022]
Abstract
Myopia is rapidly increasing in Asia and around the world, while it is recognised that complications from high myopia may cause significant visual impairment. Thus, imaging the myopic eye is important for the diagnosis of sight-threatening complications, monitoring of disease progression and evaluation of treatments. For example, recent advances in high-resolution imaging using optical coherence tomography may delineate early myopic macula pathology, optical coherence tomography angiography may aid early choroidal neovascularisation detection, while multimodal imaging is important for monitoring treatment response. However, imaging the eye with high myopia accurately has its challenges and limitations, which are important for clinicians to understand in order to choose the best imaging modality and interpret the images accurately. In this review, we present the current imaging modalities available from the anterior to posterior segment of the myopic eye, including the optic nerve. We summarise the clinical indications, image interpretation and future developments that may overcome current technological limitations. We also discuss potential biomarkers for myopic progression or development of complications, including basement membrane defects, and choroidal atrophy or choroidal thickness measurements. Finally, we present future developments in the field of myopia imaging, such as photoacoustic imaging and corneal or scleral biomechanics, which may lead to innovative treatment modalities for myopia.
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35
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Nabavizadeh A, Payen T, Saharkhiz N, McGarry M, Olive KP, Konofagou EE. Technical Note: In vivo Young's modulus mapping of pancreatic ductal adenocarcinoma during HIFU ablation using harmonic motion elastography (HME). Med Phys 2018; 45:5244-5250. [PMID: 30178474 DOI: 10.1002/mp.13170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/02/2018] [Accepted: 08/28/2018] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Noninvasive quantitative assessment of coagulated tissue during high-intensity focused ultrasound (HIFU) ablation is one of the essential steps for tumor treatment, especially in such cases as the Pancreatic Ductal Adenocarcinoma (PDA) that has low probability of diagnosis at the early stages and high probability of forming solid carcinomas resistant to chemotherapy treatment at the late stages. METHODS Harmonic motion elastography (HME) is a technique for the localized estimation of tumor stiffness. This harmonic motion imaging (HMI)-based technique is designed to map the tissue Young's modulus or stiffness noninvasively. A focused ultrasound (FUS) transducer generates an oscillating, acoustic radiation force in its focal region. The two-dimensional (2D) shear wave speed, and consequently the Young's modulus maps, is generated by tracking the radio frequency (RF) signals acquired at high frame rates. By prolonging the sonication for more than 50 s using the same methodology, the 2D Young's modulus maps are reconstructed while HIFU is applied and ablation is formed on PDA murine tumors. RESULTS The feasibility of this technique in measuring the regional Young's modulus was first assessed in tissue-mimicking phantoms. The contrast-to-noise ratio (CNR) was found to be higher than 11.7 dB for each 2D reconstructed Young's modulus map. The mean error in this validation study was found to be equal to less than 19%. Then HME was applied on two transgenic mice with pancreatic ductal adenocarcinoma tumors. The Young's modulus median value of this tumor at the start of the HIFU application was equal to 2.1 kPa while after 45 s of sonication it was found to be approximately three times stiffer (6.7 kPa). CONCLUSIONS The HME was described herein and showed its capability of measuring tissue stiffness noninvasively by measuring the shear wave speed propagation inside the tissue and reconstructing a 2D Young's modulus map. Application of the methodology in vivo and during HIFU were thus reported here for the first time.
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Affiliation(s)
| | - Thomas Payen
- Biomedical Engineering, Columbia University, New York, NY, USA
| | | | - Matthew McGarry
- Biomedical Engineering, Columbia University, New York, NY, USA
| | - Kenneth P Olive
- Departments of Medicine and Pathology & Cell Biology, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY, USA.,Department of Radiology, Columbia University Medical Center, New York, NY, USA
| | - Elisa E Konofagou
- Biomedical Engineering, Columbia University, New York, NY, USA.,Department of Radiology, Columbia University Medical Center, New York, NY, USA
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36
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Pellionisz PA, Namiri NK, Suematsu G, Hu Y, Braganza A, Rangwalla K, Denson DJ, Badran K, Francis NC, Maccabi A, Saddik G, Taylor Z, St. John MA, Grundfest WS. Vibroacoustographic System for Tumor Identification. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2018; 91:215-223. [PMID: 30258308 PMCID: PMC6153624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Oral and head and neck squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide. The primary management of OSCC relies on complete surgical resection of the tumor. Margin-free resection, however, is difficult given the devastating effects of aggressive surgery. Currently, surgeons determine where cuts are made by palpating edges of the tumor. Accuracy varies based on the surgeon's experience, the location and type of tumor, and the risk of damage to adjacent structures limiting resection margins. To fulfill this surgical need, we contrast tissue regions by identifying disparities in viscoelasticity by mixing two ultrasonic beams to produce a beat frequency, a technique termed vibroacoustography (VA). In our system, an extended focal length of the acoustic stress field yields surgeons' high resolution to detect focal lesions in deep tissue. VA offers 3D imaging by focusing its imaging plane at multiple axial cross-sections within tissue. Our efforts culminate in production of a mobile VA system generating image contrast between normal and abnormal tissue in minutes. We model the spatial direction of the generated acoustic field and generate images from tissue-mimicking phantoms and ex vivo specimens with squamous cell carcinoma of the tongue to qualitatively demonstrate the functionality of our system. These preliminary results warrant additional validation as we continue clinical trials of ex vivo tissue. This tool may prove especially useful for finding tumors that are deep within tissue and often missed by surgeons. The complete primary resection of tumors may reduce recurrence and ultimately improve patient outcomes.
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Affiliation(s)
- Peter A. Pellionisz
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA,UCLA Head and Neck Cancer Program, David Geffen School of Medicine at UCLA, Los Angeles, CA,Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA,Center for Advanced Surgical and Interventional Technology at Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA,Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Nikan K. Namiri
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA,Center for Advanced Surgical and Interventional Technology at Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Gregory Suematsu
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA
| | - Yong Hu
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA
| | - Ameet Braganza
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA
| | - Khuzaima Rangwalla
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA
| | | | - Karam Badran
- UCLA Head and Neck Cancer Program, David Geffen School of Medicine at UCLA, Los Angeles, CA,Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA
| | - Nathan C. Francis
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA
| | - Ashkan Maccabi
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA,Center for Advanced Surgical and Interventional Technology at Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - George Saddik
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA,Center for Advanced Surgical and Interventional Technology at Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Zachary Taylor
- UCLA Head and Neck Cancer Program, David Geffen School of Medicine at UCLA, Los Angeles, CA,Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA,Center for Advanced Surgical and Interventional Technology at Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Maie A. St. John
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA,UCLA Head and Neck Cancer Program, David Geffen School of Medicine at UCLA, Los Angeles, CA,Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Warren S. Grundfest
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, CA,Center for Advanced Surgical and Interventional Technology at Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA,To whom all correspondence should be addressed: Warren S. Grundfest, MD, Department of Bioengineering, 4121H Engineering V, Los Angeles, CA 90095-1624; Tel: 310-794-5550, Fax: 310-794-5956,
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37
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Jaiswal D, Tang-Schomer MD, Sood D, Kaplan DL, Hoshino K. Nondestructive, Label-Free Characterization of Mechanical Microheterogeneity in Biomimetic Materials. ACS Biomater Sci Eng 2018; 4:3259-3267. [PMID: 33435062 DOI: 10.1021/acsbiomaterials.8b00286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We propose a novel nondestructive, label-free, mechanical characterization method for composite biomimetic materials. The method combines microscale-force measurement, bright-field microscopy based deformation analysis, and finite-element methods (FEM) to study the heterogeneity in bioengineered composite materials. The method was used to study silk fibroin protein based, donut-shaped scaffolds consisting of a shell (diameter 5 mm) and a core (diameter 2 mm) with a stiff-core or a soft-core configuration. The samples were based on our previously reported bioengineered brain tissue model. Step-wise images of sample deformation were recorded as the automated mechanical stage compressed the sample. The force-compression curves were also recorded with a load cell. A MATLAB program was used to compare and match optically measured strain distribution with that found from the FEM simulations. Iterative processes are used to determine the values that best represent the elastic moduli of the shell and the core regions. The calculated moduli found from the composite models were not significantly different from the values measured separately for each material, demonstrating the efficacy of this new approach. In addition, the method successfully measured multiple distinct regions embedded in a polydimethylsiloxane block. These results demonstrated the feasibility of our method in the microheterogeneity characterization of biomimetic composite structures.
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Affiliation(s)
- Devina Jaiswal
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
| | - Min D Tang-Schomer
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Drive, Farmington, Connecticut 06032, United States
| | - Disha Sood
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Kazunori Hoshino
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
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38
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Weickenmeier J, Kurt M, Ozkaya E, Wintermark M, Pauly KB, Kuhl E. Magnetic resonance elastography of the brain: A comparison between pigs and humans. J Mech Behav Biomed Mater 2018; 77:702-710. [DOI: 10.1016/j.jmbbm.2017.08.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/23/2017] [Accepted: 08/23/2017] [Indexed: 12/12/2022]
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39
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DeJong HM, Abbott S, Zelesco M, Kennedy BF, Ziman MR, Wood FM. The validity and reliability of using ultrasound elastography to measure cutaneous stiffness, a systematic review. INTERNATIONAL JOURNAL OF BURNS AND TRAUMA 2017; 7:124-141. [PMID: 29348976 PMCID: PMC5768929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 09/28/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Ultrasound elastography is an imaging technology which can objectively and non-invasively assess tissue stiffness. It is emerging as a useful marker for disease diagnosis, progression and treatment efficacy. OBJECTIVE To examine current, published research evaluating the use of ultrasound elastography for the measurement of cutaneous or subcutaneous stiffness and to determine the level of validity and reliability, recommended methodologies and limitations. METHODS MEDLINE, Web of science and Scopus were systematically searched in August 2016 to identify original articles evaluating the use of ultrasound elastography to assess cutaneous stiffness. Relevant studies were then quality evaluated using the Quality Assessment of Diagnostic Accuracy Studies v 2 (QUADAS-2) tool and the Quality Appraisal of Reliability Studies (QAREL). RESULTS From a total of 688 articles, 14 met the inclusion criteria for full review. Within the 14 studies, elastography was used to evaluate tumors, systemic sclerosis, lymphedema, abscess, and post-radiation neck fibrosis. Only three robust studies demonstrated good interrater reliability, whereas all validity studies had low sample sizes and demonstrated risks of bias. CONCLUSION Robust evidence supporting the use of ultrasound elastography as a diagnostic tool in cutaneous conditions is low, however, initial indicators support further research to establish the utility of ultrasound elastography in dermatology.
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Affiliation(s)
- Helen M DeJong
- Perth Scar and Pain ClinicMount Pleasant, Western Australia, 6153, Australia
- School of Medical and Health Science, Edith Cowan UniversityJoondalup, Western Australia, 6027, Australia
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western AustraliaCrawley, Western Australia, 6009, Australia
| | - Steven Abbott
- Department of Medical Imaging, Fiona Stanley HospitalMurdoch, Western Australian, 6150, Australia
| | - Marilyn Zelesco
- Department of Medical Imaging, Fiona Stanley HospitalMurdoch, Western Australian, 6150, Australia
| | - Brendan F Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western AustraliaCrawley, Western Australia, 6009, Australia
- School of Electrical, Electronic and Computer Engineering, The University of Western Australia Crawley6009, Western Australia
| | - Mel R Ziman
- School of Medical and Health Science, Edith Cowan UniversityJoondalup, Western Australia, 6027, Australia
| | - Fiona M Wood
- Burn Injury Research Unit, The University of Western Australia CrawleyWestern Australia, 6009, Australia
- Burn Service of Western Australia, Fiona Stanley HospitalMurdoch, Western Australian, 6150, Australia
- Child and Adolescent Health Service of Western Australia, Princess Margaret HospitalSubiaco, Western Australia, 6008, Australia
- Fiona Wood Foundation Fiona Stanley HospitalMurdoch, Western Australian, 6150, Australia
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Li GY, Cao Y. Assessing the mechanical properties of anisotropic soft tissues using guided wave elastography: Inverse method and numerical experiments. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:1526. [PMID: 28964064 DOI: 10.1121/1.5002685] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Determining the mechanical properties of soft biological tissues can be of great importance. For example, the microstructures of many soft tissues, such as those of the human Achilles tendon, have been identified as typical anisotropic materials. This paper proposes an inverse approach that uses guided wave elastography to determine the anisotropic elastic and hyperelastic parameters of thin-walled transversely isotropic biological soft tissues. This approach was developed from the theoretical solutions for the dispersion relations of guided waves, which were derived based on a constitutive model suitable for describing the deformation behavior of such tissues. The properties of these solutions were investigated; in particular, sensitivity to data errors was addressed by introducing the concept of the condition number. To further validate the proposed inverse approach, the guided wave elastography of thin-walled transversely isotropic soft tissues was investigated using numerical experiments. The results indicated that the four constitutive parameters (other than the tensile modulus along the direction of the fibers, EL) could be determined with a good level of accuracy using this method.
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Affiliation(s)
- Guo-Yang Li
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yanping Cao
- Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
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