Efficacy of shear wave elasticity for evaluating myocardial hypertrophy in hypertensive rats.
Ontology highlight
ABSTRACT:
SUBMITTER: Takaya Y
PROVIDER: S-EPMC8613270 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Conventional multiple-track-location shear wave elasticity imaging (MTL-SWEI) is a powerful tool for noninvasively estimating tissue elasticity. The resolution and noise levels of MTL-SWEI systems, however, are limited by ultrasound speckle. Single-track-location SWEI (STL-SWEI) is a novel variant which fixes the position of the tracking beam and modulates the push location to effectively cancel out the effects of speckle-induced bias. We present here a 3-D STL-SWEI system, which provides full suppression of lateral and elevation speckle bias for high-resolution volumetric elasticity imaging, and requires no spatial smoothing to make accurate measurements of shear wave speed. We demonstrate and analyze the system's performance in homogeneous and layered elasticity phantoms.
| S-EPMC5767318 | biostudies-literature
Project description:OBJECTIVE:To investigate the correlation between Young's modulus of the thyroid tissue measured by in shear wave elastography (SWE) and the clinical manifestations of Hashimoto's thyroiditis in different stages. METHODS:A total of 104 patients with the clinical diagnosis of Hashimoto's thyroiditis were enrolled in this study, including 26 with hyperthyroidism, 29 with normal thyroid function, 27 with subclinical hypothyroidism, 22 with clinical hypothyroidism, with 50 healthy volunteers serving as the healthy control group. All the subjects underwent SWE to obtain the Young's modulus value of the thyroid tissue. Univariate analysis of variance was used to compare the Young's modulus among the groups, and Pearson correlation analysis was used to analyze the correlation between the Young's modulus of the thyroid tissue and serum levels of thyroid microsomal antibody (TMAb) and thyroid globulin antibody (TGAb). RESULTS:In the 4 groups of patients, the Young's modulus increased significantly in the order of hyperthyroidism group, normal thyroid function group, subclinical hypothyroidism group and clinical hypothyroidism group (F=60.983, P<0.01). The Young's modulus was significantly lower in hyperthyroidism group than in the other 3 groups (P<0.05), and was significantly lower in normal thyroid function group than in subclinical hypothyroidism group and clinical hypothyroidism group (P<0.05). CONCLUSION:The Young's modulus of the thyroid tissue measured by shear wave elastography is related with the clinical manifestations of Hashimoto's thyroiditis in different stages, but the relevance needs to be further confirmed by multi-center, randomized, controlled studies involving a larger sample size.
| S-EPMC6780460 | biostudies-literature
Project description:ObjectiveTo investigate the accuracy and precision of ultrasound shear wave elasticity measurements as a function of target elasticity and acquisition depth.Materials and methodsUsing five ultrasound systems (VTQ, VTIQ, EPIQ 5, Aixplorer, and Aplio 500), two operators independently measured shear wave elasticities in two phantoms containing five different target elasticities (8±3, 14±4, 25±6, 45±8, and 80±12 kPa) at depths of 15, 30, 35, and 60 mm. Accuracy was assessed by evaluating measurement errors and the proportions of outliers, while factors affecting accuracy were assessed using logistic regression analysis. Measurement errors were defined as differences between the measured values and 1) the margins of the target elasticity, and 2) the median values of the target elasticity. Outliers were defined as measured values outside the margins of the target elasticity. Precision was assessed by calculating the reproducibility of measurements using the within-subject coefficient of variation (wCV).ResultsMean measurement errors and the proportions of outliers were higher for high than for low target elasticities (p<0.001), but did not differ in relation to acquisition depth, either within an elastography system or across the different systems. Logistic regression analysis showed that target elasticity (p<0.001) significantly affected accuracy, whereas acquisition depth (p>0.05) did not. The wCV for the 80±12 kPa target (31.33%) was significantly higher than that for lower elasticity targets (6.96-10.43 kPa; p<0.001). The wCV did not differ across acquisition depths. The individual elastography systems showed consistent results.ConclusionsTargets with high elasticity showed lower accuracy and lower precision than targets with low elasticity, while acquisition depth did not show consistent patterns in either accuracy or precision.
| S-EPMC6622533 | biostudies-literature
Project description:Changes in myocardial stiffness may represent a valuable biomarker for early tissue injury or adverse remodeling. In this study, we developed and validated a novel transducer-free magnetic resonance elastography (MRE) approach for quantifying myocardial biomechanics using aortic valve closure-induced shear waves. Using motion-sensitized two-dimensional pencil beams, septal shear waves were imaged at high temporal resolution. Shear wave speed was measured using time-of-flight of waves travelling between two pencil beams and corrected for geometrical biases. After validation in phantoms, results from twelve healthy volunteers and five cardiac patients (two left ventricular hypertrophy, two myocardial infarcts, and one without confirmed pathology) were obtained. Torsional shear wave speed in the phantom was 3.0 ± 0.1 m/s, corresponding with reference speeds of 2.8 ± 0.1 m/s. Geometrically-biased flexural shear wave speed was 1.9 ± 0.1 m/s, corresponding with simulation values of 2.0 m/s. Corrected septal shear wave speeds were significantly higher in patients than healthy volunteers [14.1 (11.0-15.8) m/s versus 3.6 (2.7-4.3) m/s, p = 0.001]. The interobserver 95%-limits-of-agreement in healthy volunteers were ± 1.3 m/s and interstudy 95%-limits-of-agreement - 0.7 to 1.2 m/s. In conclusion, myocardial shear wave speed can be measured using aortic valve closure-induced shear waves, with cardiac patients showing significantly higher shear wave speeds than healthy volunteers. This non-invasive measure may provide valuable insights into the pathophysiology of heart failure.
| S-EPMC7809276 | biostudies-literature
Project description:BackgroundWe aimed to observe the relationship between the pathological components of a deep venous thrombus (DVT), which was divided into three parts, and the findings on quantitative ultrasonic shear wave elastography (SWE) to increase the accuracy of thrombus staging in a rabbit model.MethodsA flow stenosis-induced vein thrombosis model was used, and the thrombus was divided into three parts (head, body and tail), which were associated with corresponding observation points. Elasticity was quantified in vivo using SWE over a 2-week period. A quantitative pathologic image analysis (QPIA) was performed to obtain the relative percentages of the components of the main clots.ResultsDVT maturity occurred at 2 weeks, and the elasticity of the whole thrombus and the three parts (head, body and tail) showed an increasing trend, with the Young's modulus values varying from 2.36 ± 0.41 kPa to 13.24 ± 1.71 kPa; 2.01 ± 0.28 kPa to 13.29 ± 1.48 kPa; 3.27 ± 0.57 kPa to 15.91 ± 2.05 kPa; and 1.79 ± 0.36 kPa to 10.51 ± 1.61 kPa, respectively. Significant increases occurred on different days for the different parts: the head showed significant increases on days 4 and 6; the body showed significant increases on days 4 and 7; and the tail showed significant increases on days 3 and 6. The QPIA showed that the thrombus composition changed dynamically as the thrombus matured, with the fibrin and calcium salt deposition gradually increasing and the red blood cells (RBCs) and platelet trabecula gradually decreasing. Significant changes were observed on days 4 and 7, which may represent the transition points for acute, sub-acute and chronic thrombi. Significant heterogeneity was observed between and within the thrombi.ConclusionsVariations in the thrombus components were generally consistent between the SWE and QPIA. Days 4 and 7 after thrombus induction may represent the transition points for acute, sub-acute and chronic thrombi in rabbit models. A dynamic examination of the same part of the thrombus may be helpful for improving the sensitivity and reproducibility of SWE for DVT diagnosis and staging.
| S-EPMC5470690 | biostudies-literature
Project description:Ultrasound elasticity imaging has been developed over the last decade to estimate tissue stiffness. Shear wave elasticity imaging (SWEI) quantifies tissue stiffness by measuring the speed of propagating shear waves following acoustic radiation force excitation. This paper presents the sequencing and data processing protocols of SWEI using a Verasonics system. The selection of the sequence parameters in a Verasonics programming script is discussed in detail. The data processing pipeline to calculate group shear wave speed (SWS), including tissue motion estimation, data filtering, and SWS estimation, is demonstrated. In addition, the procedures for calibration of beam position, scanner timing, and transducer face heating are provided to avoid SWS measurement bias and transducer damage.
| S-EPMC5266610 | biostudies-other
Project description:The elastic properties of the Achilles tendon (AT) are altered in local injury or other diseases and in response to changes in mechanical load. Recently, elastography has been used to evaluate variations in tendon elastic properties, mainly among healthy individuals or athletes. Therefore, this study evaluated the biomechanical changes in ATs in individuals with and without plantar fasciitis (PF). The purposes were as follows: (1) to evaluate the passive stiffness of three regions of the AT which defined as 0 (AT0 cm), 3 (AT3 cm), and 6 cm (AT6 cm) above the calcaneal tuberosity in participants with and without PF, (2) to investigate the interplay between the passive stiffness in patients with PF and pain, (3) to detect optimal cut-off points of stiffness of the AT in assessing individuals with chronic PF, and (4) to determine the correlation between the plantar fascia thickness (PFT) and pain. This cross-sectional study included 40 participants (mean age = 51 ± 13 years). When the ankle was in a relaxed position, patients with PF experienced increased passive stiffness in AT0 cm (p = 0.006) and AT3 cm (P = 0.003), but not in the neutral position. Significant correlations were observed between pain and stiffness of AT (AT0 cm r = 0.489, P = 0.029; AT3 cm r = 487, P = 0.030; AT6 cm r = 0.471, P = 0.036), but not in the PFT (P = 0.557). Optimal cut-off stiffness was AT (452 kPa) in the relaxed ankle position. The plantar fascia of patients with PF was significantly thicker than that of the controls (P < 0.001). Findings from the present study demonstrate that tendon stiffness is a good indicator of the clinical situation of patients with PF. Monitoring passive tendon stiffness may provide additional information to assess severity of the condition and guide therapeutic. The treatment programs for PF should also be tailored to the distal AT, as conventional therapy might not be targeted to tight tendons.
| S-EPMC8257043 | biostudies-literature
Project description:BackgroundShear waves are generated by the closure of the heart valves. Significant differences in shear wave velocity have been found recently between normal myocardium and disease models of diffusely increased muscle stiffness. In this study we correlate in vivo myocardial shear wave imaging (SWI) with presence of scarred tissue, as model for local increase of stiffness. Stiffness variation is hypothesized to appear as velocity variation.MethodsTen healthy volunteers (group 1), 10 hypertrophic cardiomyopathy (HCM) patients without any cardiac intervention (group 2), and 10 HCM patients with prior septal reduction therapy (group 3) underwent high frame rate tissue Doppler echocardiography. The SW in the interventricular septum after aortic valve closure was mapped along two M-mode lines, in the inner and outer layer.ResultsWe compared SWI to 3D echocardiography and strain imaging. In groups 1 and 2, no change in velocity was detected. In group 3, 8/10 patients showed a variation in SW velocity. All three patients having transmural scar showed a simultaneous velocity variation in both layers. Out of six patients with endocardial scar, five showed variations in the inner layer.ConclusionLocal variations in stiffness, with myocardial remodeling post septal reduction therapy as model, can be detected by a local variation in the propagation velocity of naturally occurring shear waves.
| S-EPMC7525991 | biostudies-literature
Project description:The occurrence of the pulmonary capillary hemorrhage (PCH) bioeffect of diagnostic ultrasound in rats was investigated for a SuperSonic Imagine shear wave elastography system (Aixplorer, Supersonic Imagine, Aix-en-Provence, France). The elastography imaging repeated at 1 Hz and consisted of widely spaced B-mode image pulses, supersonic push (SSP) pulses and shear wave imaging (SWI) pulses. Groups of rats anesthetized with ketamine and xylazine, or with ketamine only, were imaged on their right side in a warm water bath for one frame, 30 s and 300 s. The image focus and region of interest were adjusted to give exposure only with the background B-mode imaging, or primarily with the SSP and SWI pulses. A sham group had only low power aiming scans. The lungs were removed 5 min after exposure and evaluated for PCH area and volume. The B mode was notably ineffective and produced significant PCH only at the maximum 0 dB output. The SSP pulses together with the SWI pulses produced significant PCH for 300 s, 30 s and even single image exposures. Peak rarefactional pressure amplitude PCH thresholds for 300 s exposure were the same with or without the B-mode pulses at 1.5 MPa (in situ mechanical index, MIIS?=?0.67). A 30 s duration resulted in a slightly increased threshold of 1.7 MPa (MIIS?=?0.76). The omission of xylazine from the anesthetic, which reduces the sensitivity of rat lung to PCH occurrence, resulted in an increased threshold of 2.1 MPa (MIIS?=?0.94). The unique SSP pulses were much more effective than the B mode, but thresholds were comparable to previous results with other diagnostic ultrasound modes on other systems.
| S-EPMC6768750 | biostudies-literature
Project description:Arterial hypertension (AH) is associated with heart and chronic kidney disease (CKD). However, the precise mechanisms of myocardial remodeling (MR) in the settings of CKD remain elusive. We hypothesized that TRPC6, calcineurin/NFAT, and Wnt/β-catenin signaling pathways are involved in the development of MR in the background of CKD and AH. Early CKD was induced by performing a 5/6 nephrectomy (5/6NE) in spontaneously hypertensive rats (SHR-NE). Sham-operated (SO) SHR (SHR-SO) and Wistar Kyoto (WKY-SO) rats served as controls. Systolic blood pressure (SBP), heart rate, myocardial mass index (MMI), serum creatinine, cardiomyocyte diameter (dCM), myocardial fibrosis (MF), serum and kidney α-Klotho levels, myocardial expression of calcineurin (CaN), TRPC6, and β-catenin were measured two months after 5/6NE or SO. NE-induced kidney dysfunction corresponded to mild-to-moderate human CKD and was associated with an increase in FGF23 and a decrease in renal α-Klotho. The levels of SBP, MMI, dCM, and MF were higher in SHRs compared to WKY-SO as well as in SHR-NE vs. SHR-SO. The MR was associated with increased cardiomyocyte expression of CaN/NFAT and β-catenin along with its intracellular re-distribution. TRPC6 protein levels were substantially elevated in both SHR groups with higher Trpc6 mRNA expression in SHR-NE. The Wnt/β-catenin and TRPC6/CaN/NFAT hypertrophic signaling pathways seem to be involved in myocardial remodeling in the settings of AH and CKD and might be mediated by FGF23 and α-Klotho axis.
| S-EPMC8124394 | biostudies-literature