A Coupled Tube-Tissue Model for Frequency Calculation of Arterial Tubes With Tissue

2003 ◽  
Author(s):  
Xiaoming Zhang ◽  
Mostafa Fatemi ◽  
James F. Greenleaf
Keyword(s):  
Vibration Analysis ◽  
Tissue Characterization ◽  
Experimental Studies ◽  
Radiation Force ◽  
Imaging Method ◽  
Large Artery ◽  
Rubber Tube ◽  
Tissue Model ◽  
Frequency Calculation

Vibro-acoustography is a new noncontact imaging method based on the radiation force of ultrasound. We extend this new technique for tissue characterization of arterial vessels by vibration techniques. In this paper a theoretical model for vibration analysis of arterial vessel with tissue is developed. Experimental studies were carried out on a silicone rubber tube embedded in a cylindrical gelatin phantom of larger radius, which simulates a large artery and the tissue body. The fundamental mode is well excited by the radiation force of ultrasound. The fundamental frequency was measured 81.8 Hz for a tube-phantom structure that is quite close to our theoretical prediction of 83.3 Hz.

Application of Topological Sensitivity Toward Soft-Tissue Characterization From Vibroacoustography Measurements

2013 ◽  
Vol 8 (3) ◽  
Author(s):  
Huina Yuan ◽  
Bojan B. Guzina ◽  
Shigao Chen ◽  
Randall Kinnick ◽  
Mostafa Fatemi
Keyword(s):  
Tissue Characterization ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Imaging Method ◽  
Topological Sensitivity ◽  
Vibration Data ◽  
Viscoelastic Parameters ◽  
Resolution Imaging ◽  
Lesion Characterization

This study concerns the development and preliminary experimental verification of a topological sensitivity–based platform for the material characterization of tissue anomalies exposed by vibroacoustography-type imaging techniques. Vibroacoustography (VA) is a high-resolution imaging method that has been applied to the detection of pathological changes in soft tissues. Although the data provided by this method is related to the mechanical properties of tissue, the viscoelastic parameters of the object cannot be estimated by this imaging method itself. Topological sensitivity (TS) method is a data processing methodology that can be used to estimate the viscoelastic parameters of an object from vibration data. In this study, the concept of topological sensitivity is applied to interpret the vibroacoustography measurements for the purpose of lesion characterization. In the proposed approach, the topological sensitivity function, which signifies the variation of a given cost functional when an infinitesimal inclusion with trial material parameters is placed at the location of a point force, is formulated in terms of the adjoint field. The effectiveness of the resulting formula as a material indicator for lesion characterization is demonstrated by estimating the relative elastic parameters of a well-controlled neoprene sphere embedded in a tissue-mimicking phantom specimen.

Synthesis and characterization of L-threonine ammonium bromide: grown on single crystal with experimental studies on NLO

2021 ◽  
Vol 44 (3) ◽  
Author(s):  
T KALAIARASI ◽  
M SENTHILKUMAR ◽  
S SHANMUGAN ◽  
T JARIN ◽  
V CHITHAMBARAM ◽  
...  
Keyword(s):  
Single Crystal ◽  
Experimental Studies ◽  
Synthesis And Characterization ◽  
Ammonium Bromide

scholarly journals Introduction of the Grayscale Median for Ultrasound Tissue Characterization of the Transplanted Kidney

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 390
Author(s):  
Camilo G. Sotomayor ◽  
Stan Benjamens ◽  
Hildebrand Dijkstra ◽  
Derya Yakar ◽  
Cyril Moers ◽  
...  
Keyword(s):  
Kidney Transplant ◽  
Tissue Characterization ◽  
Kidney Transplant Recipients ◽  
Systematic Assessment ◽  
Ultrasound Tissue Characterization ◽  
Adult Kidney ◽  
Mersenne Twister ◽  
History Of

Ultrasound examination is advised for early post-kidney transplant assessment. Grayscale median (GSM) quantification is novel in the kidney transplant field, with no systematic assessment previously reported. In this prospective cohort study, we measured the post-operative GSM in a large cohort of adult kidney transplant recipients (KTR) who consecutively underwent Doppler ultrasound directly after transplantation (within 24 h), compared it with GSM in nontransplanted patients, and investigated its association with baseline and follow-up characteristics. B-mode images were used to calculate the GSM in KTR and compared with GSM data in nontransplanted patients, as simulated from summary statistics of the literature using a Mersenne twister algorithm. The association of GSM with baseline and 1-year follow-up characteristics were studied by means of linear regression analyses. In 282 KTR (54 ± 15 years old, 60% male), the median (IQR) GSM was 55 (45–69), ranging from 22 to 124 (coefficient of variation = 7.4%), without differences by type of donation (p = 0.28). GSM in KTR was significantly higher than in nontransplanted patients (p < 0.001), and associated with systolic blood pressure, history of cardiovascular disease, and donor age (std. β = 0.12, −0.20, and 0.13, respectively; p < 0.05 for all). Higher early post-kidney transplant GSM was not associated with 1-year post-kidney transplant function parameters (e.g., measured and estimated glomerular filtration rate). The data provided in this study could be used as first step for further research on the application of early postoperative ultrasound in KTR.

Characterization of lung ultrasound imaging in preterm infants with bronchopulmonary dysplasia

2021 ◽  
pp. 1-13
Author(s):  
Ying-Hua Sun ◽  
Lin Yuan ◽  
Yang Du ◽  
Jian-Guo Zhou ◽  
Sam Bill Lin ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Bronchopulmonary Dysplasia ◽  
Neonatal Intensive Care ◽  
Lung Ultrasound ◽  
Imaging Method ◽  
Chronic Lung Diseases ◽  
Pleural Line ◽  
Ultrasound Features

BACKGROUND: Lung ultrasound (LUS) is a bedside technique that can be used on diagnosis and follow-up of neonatal respiratory diseases. However, there are rare reports on the ultrasound features of bronchopulmonary dysplasia (BPD) which is one of the most common chronic lung diseases in preterm infants. OBJECTIVE: To describe the ultrasound features of different BPD levels, and to investigate the value of ultrasound in evaluating moderate-to-severe BPD. METHODS: In this prospective cohort study, newborns of less than 37 weeks’ gestational age in neonatal intensive care unit (NICU) were included. The LUS characteristics including pleural line, alveolar-interstitial syndrome (AIS), retrodiaphragmatic hyperechogenicity and diaphragmatic morphology were observed and recorded. The reliability of LUS in evaluating moderate and severe BPD were compared and calculated. RESULTS: A total of 108 infants were enrolled in our study: 39, 24, 29, 16 infants had non, mild, moderate and severe BPD. The median(IQR) pleura thickness in the moderate-to-severe BPD group was 1.7(1.6–1.85) mm, which was thicker than that in the none-to-mild BPD infants (P <  0.001), meanwhile the proportions of rough pleural lines, diffuse AIS, retrodiaphragmatic hyperechogenicity, small cysts above the diaphragm and rough diaphragm in the moderate-to-severe BPD group were also higher than those in none-to-mild BPD group (86.7% vs 36.5, 57.8% vs 7.9%, 37.8% vs 0, 33.3% vs 0, P <  0.001). In evaluating moderate-to-severe BPD, rough pleura had 91.1% (95% confidence interval [CI]: 0.793–0.965) in sensitivity, 91.3% (95% CI: 0.797–0.966) in negative predictive value (NPV), and 66.7% (95% CI: 0.544–0.771) in specificity. Small cysts had 100% (95% CI: 0.941-1) in specificity, 100% (95% CI: 0.816-1) in PPV, and 37.8% in sensitivity (95% CI: 0.251–0.524). Rough diaphragm had 100% (95% CI: 0.943-1) in sensitivity, 100% (95% CI: 0.796-1) in PPV and 33.3% (95% CI: 0.211–0.478) in specificity. CONCLUSIONS: Depending on its unique advantages such as convenient, no radiation and repeatable, LUS is a valuable imaging method in assessing the severity of BPD, especially in moderate and severe BPD.

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