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Geometry Does Impact on the Plane Strain Directions of the Human Left Ventricle, Irrespective of Disease. J Cardiovasc Dev Dis 2022; 9:jcdd9110393. [DOI: 10.3390/jcdd9110393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/04/2022] [Accepted: 11/10/2022] [Indexed: 11/17/2022] Open
Abstract
The directions of primary strain lines of local deformation in Epicardial and Endocardial layers have been the subject of debate in recent years. Different methods led to different conclusions and a complete assessment of strain direction patterns in large and variable (in terms of pathology) cohorts of healthy and diseased patients is still lacking. Here, we use local deformation tensors in order to evaluate the angle of strain lines with respect to the horizontal circumferential direction in both Epi- and Endo-layers. We evaluated this on a large group of 193 subjects including 82 healthy control and 111 patients belonging to a great variety of pathological conditions. We found that Epicardial strain lines obliquely directed while those of Endocardium are almost circumferential. This result occurs irrespective of pathological condition. We propose that the geometric vinculum characterizing Endocardium and Epicardium in terms of different lever arm length and orientation of muscular fibers during contraction inescapably requires Endocardial strain lines to be circumferentially oriented and this is corroborated by experimental results. Further investigations on transmural structure of myocytes could couple results presented here in order to furnish additional experimental explanations.
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Golemati S, Cokkinos DD. Recent advances in vascular ultrasound imaging technology and their clinical implications. ULTRASONICS 2022; 119:106599. [PMID: 34624584 DOI: 10.1016/j.ultras.2021.106599] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 08/26/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
In this paper recent advances in vascular ultrasound imaging technology are discussed, including three-dimensional ultrasound (3DUS), contrast-enhanced ultrasound (CEUS) and strain- (SE) and shear-wave-elastography (SWE). 3DUS imaging allows visualisation of the actual 3D anatomy and more recently of flow, and assessment of geometrical, morphological and mechanical features in the carotid artery and the aorta. CEUS involves the use of microbubble contrast agents to estimate sensitive blood flow and neovascularisation (formation of new microvessels). Recent developments include the implementation of computerised tools for automated analysis and quantification of CEUS images, and the possibility to measure blood flow velocity in the aorta. SE, which yields anatomical maps of tissue strain, is increasingly being used to investigate the vulnerability of the carotid plaque, but is also promising for the coronary artery and the aorta. SWE relies on the generation of a shear wave by remote acoustic palpation and its acquisition by ultrafast imaging, and is useful for measuring arterial stiffness. Such advances in vascular ultrasound technology, with appropriate validation in clinical trials, could positively change current management of patients with vascular disease, and improve stratification of cardiovascular risk.
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Affiliation(s)
- Spyretta Golemati
- Medical School, National and Kapodistrian University of Athens, Athens, Greece.
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3
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Wang D, Chayer B, Destrempes F, Gesnik M, Tournoux F, Cloutier G. Deformability of ascending thoracic aorta aneurysms assessed using ultrafast ultrasound and a principal strain estimator: In vitro evaluation and in vivo feasibility. Med Phys 2022; 49:1759-1775. [PMID: 35045186 DOI: 10.1002/mp.15464] [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: 07/15/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Noninvasive vascular strain imaging under conventional line-by-line scanning has a low frame rate and lateral resolution, and depends on the coordinate system. It is thus affected by high deformations due to image decorrelation between frames. PURPOSE To develop an ultrafast time-ensemble regularized tissue-Doppler optical-flow principal strain estimator for aorta deformability assessment in a long-axis view. METHODS This approach alleviated the impact of lateral resolution using image compounding and that of the coordinate system dependency using principal strain. Accuracy and feasibility were evaluated in two aorta-mimicking phantoms first, and then in four age-matched individuals with either a normal aorta or a pathological ascending thoracic aorta aneurysm (TAA). RESULTS Instantaneous aortic maximum and minimum principal strain maps and regional accumulated strains during each cardiac cycle were estimated at systolic and diastolic phases to characterize the normal aorta and TAA. In vitro, principal strain results matched sonomicrometry measurements. In vivo, a significant decrease in maximum and minimum principal strains was observed in TAA cases, whose range was respectively 7.9 ± 6.4% and 8.2 ± 2.6% smaller than in normal aortas. CONCLUSIONS The proposed principal strain estimator showed an ability to potentially assess TAA deformability, which may provide an individualized and reliable evaluation method for TAA rupture risk assessment. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Diya Wang
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 71049, P. R. China.,Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada
| | - Boris Chayer
- Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada
| | - François Destrempes
- Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada
| | - Marc Gesnik
- Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada
| | - François Tournoux
- Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada.,Department of Cardiology, Echocardiography Laboratory, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada
| | - Guy Cloutier
- Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital, Montreal, QC, H2×0A9, Canada.,Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, University of Montreal, Montreal, QC, H3C 3J7, Canada
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Kolosova OY, Karelina PA, Vasil'ev VG, Grinberg VY, Kurochkin II, Kurochkin IN, Lozinsky VI. Cryostructuring of polymeric systems. 58. Influence of the H2N-(CH2) -COOH–type amino acid additives on formation, properties, microstructure and drug release behaviour of poly(vinyl alcohol) cryogels. REACT FUNCT POLYM 2021. [DOI: 10.1016/j.reactfunctpolym.2021.105010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Nayak R, MacNeill J, Flores C, Webb J, Fatemi M, Alizad A. Quantitative assessment of ensemble coherency in contrast-free ultrasound microvasculature imaging. Med Phys 2021; 48:3540-3558. [PMID: 33942320 PMCID: PMC8362033 DOI: 10.1002/mp.14918] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 11/09/2022] Open
Abstract
Purpose Contrast‐free visualization of microvascular blood flow (MBF) using ultrasound can play a valuable role in diagnosis and detection of diseases. In this study, we demonstrate the importance of quantifying ensemble coherence for robust MBF imaging. We propose a novel approach to quantify ensemble coherence by estimating the local spatiotemporal correlation (LSTC) image, and evaluate its efficacy through simulation and in vivo studies. Methods The in vivo patient studies included three volunteers with a suspicious breast tumor, 15 volunteers with a suspicious thyroid tumor, and two healthy volunteers for renal MBF imaging. The breast data displayed negligible prior motion and were used for simulation analysis involving synthetically induced motion, to assess its impact on ensemble coherency and motion artifacts in MBF images. The in vivo thyroid data involved complex physiological motion due to its proximity to the pulsating carotid artery, which was used to assess the in vivo efficacy of the proposed technique. Further, in vivo renal MBF images demonstrated the feasibility of using the proposed ensemble coherence metric for curved array‐based MBF imaging involving phase conversion. All ultrasound data were acquired at high imaging frame rates and the tissue signal was suppressed using spatiotemporal clutter filtering. Thyroid tissue motion was estimated using two‐dimensional normalized cross correlation‐based speckle tracking, which was subsequently used for ensemble motion correction. The coherence of the MBF image was quantified based on Casorati correlation of the Doppler ensemble. Results The simulation results demonstrated that an increase in ensemble motion corresponded with a decrease in ensemble coherency, which reciprocally degraded the MBF images. Further the data acquired from breast tumors demonstrated higher ensemble coherency than that from thyroid tumors. Motion correction improved the coherence of the thyroid MBF images, which substantially improved its visualization. The proposed coherence metrics were also useful in assessing the ensemble coherence for renal MBF imaging. The results also demonstrated that the proposed coherence metric can be reliably estimated from downsampled ensembles (by up to 90%), thus allowing improved computational efficiency for potential applications in real‐time MBF imaging. Conclusions This pilot study demonstrates the importance of assessing ensemble coherency in contrast‐free MBF imaging. The proposed LSTC image quantified coherence of the Doppler ensemble for robust MBF imaging. The results obtained from this pilot study are promising, and warrant further development and in vivo validation.
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Affiliation(s)
- Rohit Nayak
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA
| | - Justin MacNeill
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA
| | - Cecilia Flores
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA
| | - Jeremy Webb
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA
| | - Mostafa Fatemi
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA
| | - Azra Alizad
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, USA
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Author Correction: Impact of imaging cross-section on visualization of thyroid microvessels using ultrasound: Pilot study. Sci Rep 2020; 10:11965. [PMID: 32665701 PMCID: PMC7360610 DOI: 10.1038/s41598-020-69042-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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7
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Increased carotid artery wall stiffness and plaque prevalence in HIV infected patients measured with ultrasound elastography. Eur Radiol 2020; 30:3178-3187. [DOI: 10.1007/s00330-020-06660-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/17/2019] [Accepted: 01/17/2020] [Indexed: 12/27/2022]
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8
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Nayak R, Fatemi M, Alizad A. Adaptive background noise bias suppression in contrast-free ultrasound microvascular imaging. Phys Med Biol 2019; 64:245015. [PMID: 31855574 PMCID: PMC7241295 DOI: 10.1088/1361-6560/ab5879] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Non-invasive, contrast-free imaging of small vessel blood flow is diagnostically invaluable for detection, diagnosis and monitoring of disease. Recent advances in ultrafast imaging and tissue clutter-filtering have considerably improved the sensitivity of power Doppler (PD) imaging in detecting small vessel blood flow. However, suppression of tissue clutter exposes the depth-dependent time-gain compensated noise bias that noticeably degrades the PD image. We hypothesized that background suppression of PD images based on noise bias estimated from the entire clutter-filtered singular value spectrum can considerably improve flow signal visualization compared to currently existing techniques. To test our hypothesis, in vivo experiments were conducted on suspicious breast lesions in 10 subjects and deep-seated hepatic and renal microvasculatures in four healthy volunteers. Ultrasound PD images were acquired using a clinical ultrasound scanner, implemented with compounded plane wave imaging. The time gain compensated noise field was computed from the clutter-filtered Doppler ensemble (CFDE) based on its local spatio-temporal correlation, combined with low-rank signal estimation. Subsequently, the background bias in the PD images was suppressed by subtracting the estimated noise field. Background-suppressed PD images obtained using the proposed technique substantially improved visualization of the blood flow signal. The background bias in the noise suppressed PD images varied <0.6 dB, independent of depth, which otherwise increased up to 13.8 dB. Further, the results demonstrated that the proposed technique efficaciously suppressed the background noise bias associated with smaller Doppler ensembles, which are challenging due to increased overlap between blood flow and noise components in the singular value spectrum. These preliminary results demonstrate the utility of the proposed technique to improve the visualization of small vessel blood flow in contrast-free PD images. The results of this feasibility study were encouraging, and warrant further development and additional in vivo validation.
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Affiliation(s)
- Rohit Nayak
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, MN 55902, United States of America
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Chayer B, van den Hoven M, Cardinal MHR, Li H, Swillens A, Lopata R, Cloutier G. Atherosclerotic carotid bifurcation phantoms with stenotic soft inclusions for ultrasound flow and vessel wall elastography imaging. ACTA ACUST UNITED AC 2019; 64:095025. [DOI: 10.1088/1361-6560/ab1145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Meshram NH, Mitchell CC, Wilbrand SM, Dempsey RJ, Varghese T. In vivo carotid strain imaging using principal strains in longitudinal view. Biomed Phys Eng Express 2019; 5. [PMID: 31240113 DOI: 10.1088/2057-1976/ab15c9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Carotid plaque rupture can result in stroke or transient ischemic attack that can be devastating for patients. Ultrasound strain imaging provides a noninvasive method to identify unstable plaque likely to rupture. Axial, lateral and shear strains in carotid plaque have been shown to be linked to carotid plaque instability. Recently, there has been interest in using principal strains, which do not depend on angle of insonification of the carotid artery for quantifying instability in plaque along the longitudinal view. In this work relationships between angle dependent axial, lateral and shear strain along with axis independent principal strains are compared. Three strain indices were defined, 1) Average Mean Strain (AMS), 2) Maximum Mean Strain (MMS) and 3) Mean Standard Deviation (MSD) to identify relationships between these five strain image types in a group of 76 in vivo patients. The maximum principal strain demonstrated the highest strain values when compared to axial strain for all patients with a linear regression slope of 1.6 and a y intercept of 2.4 percent strain for AMS. The maximum shear strain when compared to shear strain had a slope of 1.15 and a y intercept of 0.21 percent for AMS. Next, the effect of insonification angle, which is the angle subtended by the artery at the location of plaque was studied. Patients were divided into three sub groups, i.e. less than 5 degrees (n = 31), between 5 and 10 degrees (n = 24) and above 10 degrees (n = 21). The angle of insonification did not make a significant difference between the three angle groups when comparing the relationship between the angle dependent and independent strain values.
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Affiliation(s)
- N H Meshram
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706.,Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - C C Mitchell
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706
| | - S M Wilbrand
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706
| | - R J Dempsey
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706
| | - T Varghese
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706.,Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin, 53706
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Nayak R, Kumar V, Webb J, Fatemi M, Alizad A. Non-invasive Small Vessel Imaging of Human Thyroid Using Motion-Corrected Spatiotemporal Clutter Filtering. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1010-1018. [PMID: 30718145 PMCID: PMC6391182 DOI: 10.1016/j.ultrasmedbio.2018.10.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 09/13/2018] [Accepted: 10/22/2018] [Indexed: 05/08/2023]
Abstract
Reliable assessment of small vessel blood flow in the thyroid, without using any contrast agents, can be challenging because of increased physiological motion resulting from its proximity to the pulsating carotid artery. In this study, we hypothesized that correction of tissue motion prior to singular value decomposition (SVD)-based clutter filtering can improve the coherency of the tissue components and, thus, may allow better clutter suppression and visualization of small vessels in the thyroid. We corroborated this hypothesis by conducting phantom and in vivo studies using a clinical ultrasound scanner implemented with compounded plane wave imaging. The phantom studies were conducted using a homogeneous tissue-mimicking phantom to study the impact of motion on the covariance of the spatiotemporal Doppler data, in the absence of blood activity. The non-invasive in vivo study was conducted on a 74-y-old woman with a thyroid nodule suspicious of malignancy. A rigid body-based motion correction was performed using tissue displacements obtained from 2-D normalized cross-correlation-based speckle tracking. Subsequently, the power Doppler images were computed using SVD-based spatiotemporal clutter filtering. The results from the phantom study revealed that motion can considerably reduce the covariance of the spatiotemporal data and, thus, increase the rank of the tissue components. When the phantom was subjected to a total translation displacement of 6 pixels over the entire ensemble, in each direction (axial and lateral), the covariance dropped by more than 25%. The results obtained from the non-invasive in vivo study indicated that visualization of small vessel blood flow improved with motion correction of the power Doppler ensemble. The contrast-to-noise ratio of the blood signal in motion-corrected power Doppler images was considerably higher (8.17 and 8.32 dB), compared with that obtained using the standard SVD approach at an optimal threshold (0.87 and 4.33 dB) and a lower singular value threshold (1.92 and 3.05 dB). Further, the covariance of the in vivo thyroid spatiotemporal data increased by approximately 10% with motion correction. These preliminary results indicate that motion correction can be used to improve the visualization of small vessel blood flow in the thyroid, without using any contrast agents. The results of this feasibility study were encouraging, and warrant further development and more in vivo validation in moving tissues and organs.
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Affiliation(s)
- Rohit Nayak
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
- Corresponding Author: Azra Alizad ()
| | - Viksit Kumar
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
| | - Jeremy Webb
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
| | - Mostafa Fatemi
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
| | - Azra Alizad
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, 55902, United States
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Torres G, Czernuszewicz TJ, Homeister JW, Caughey MC, Huang BY, Lee ER, Zamora CA, Farber MA, Marston WA, Huang DY, Nichols TC, Gallippi CM. Delineation of Human Carotid Plaque Features In Vivo by Exploiting Displacement Variance. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2019; 66:481-492. [PMID: 30762544 PMCID: PMC7952026 DOI: 10.1109/tuffc.2019.2898628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
While in vivo acoustic radiation force impulse (ARFI)-induced peak displacement (PD) has been demonstrated to have high sensitivity and specificity for differentiating soft from stiff plaque components in patients with carotid plaque, the parameter exhibits poorer performance for distinguishing between plaque features with similar stiffness. To improve discrimination of carotid plaque features relative to PD, we hypothesize that signal correlation and signal-to-noise ratio (SNR) can be combined, outright or via displacement variance. Plaque feature detection by displacement variance, evaluated as the decadic logarithm of the variance of acceleration and termed "log(VoA)," was compared to that achieved by exploiting SNR, cross correlation coefficient, and ARFI-induced PD outcome metrics. Parametric images were rendered for 25 patients undergoing carotid endarterectomy, with spatially matched histology confirming plaque composition and structure. On average, across all plaques, log(VoA) was the only outcome metric with values that statistically differed between regions of lipid-rich necrotic core (LRNC), intraplaque hemorrhage (IPH), collagen (COL), and calcium (CAL). Further, log(VoA) achieved the highest contrast-to-noise ratio (CNR) for discriminating between LRNC and IPH, COL and CAL, and grouped soft (LRNC and IPH) and stiff (COL and CAL) plaque components. More specifically, relative to the previously demonstrated ARFI PD parameter, log(VoA) achieved 73% higher CNR between LRNC and IPH and 59% higher CNR between COL and CAL. These results suggest that log(VoA) enhances the differentiation of LRNC, IPH, COL, and CAL in human carotid plaques, in vivo, which is clinically relevant to improving stroke risk prediction and medical management.
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