Direct sampling and baseband conversion in Doppler systems for high-frequency ultrasound blood flow measurements

2005 ◽  
Vol 41 (14) ◽  
pp. 789 ◽  
Author(s):  
M. Vogt
Keyword(s):  
Blood Flow ◽  
High Frequency ◽  
High Frequency Ultrasound ◽  
Flow Measurements ◽  
Direct Sampling ◽  
Blood Flow Measurements ◽  
Frequency Ultrasound

In vivo imaging of blood flow in the mouse Achilles tendon using high-frequency ultrasound

Ultrasonics ◽  
2009 ◽  
Vol 49 (2) ◽  
pp. 226-230 ◽  
Author(s):  
Chih-Kuang Yeh ◽  
Jia-Jiun Chen ◽  
Meng-Lin Li ◽  
Jer-Junn Luh ◽  
Jia-Jin Jason Chen
Keyword(s):  
Blood Flow ◽  
Achilles Tendon ◽  
In Vivo Imaging ◽  
High Frequency ◽  
High Frequency Ultrasound ◽  
Frequency Ultrasound

scholarly journals Evaluation of Cerebrovascular Impedance and Wave Reflection in Mouse by Ultrasound

2015 ◽  
Vol 35 (3) ◽  
pp. 521-526 ◽  
Author(s):  
Christopher K Macgowan ◽  
Sarah Joy Stoops ◽  
Yu-Qing Zhou ◽  
Lindsay S Cahill ◽  
John G Sled
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
High Frequency ◽  
Input Impedance ◽  
Wave Reflection ◽  
Arterial Compliance ◽  
High Frequency Ultrasound ◽  
Microvascular Changes ◽  
Total Arterial Compliance ◽  
Frequency Ultrasound

Genetic and surgical mouse models are commonly used to study cerebrovascular disease, but their size makes invasive hemodynamic testing technically challenging. The purpose of this study was to demonstrate a noninvasive measurement of cerebrovascular impedance and wave reflection in mice using high-frequency ultrasound in the left common carotid artery (LCCA), and to examine whether microvascular changes associated with hypercapnia could be detected with such an approach. Ten mice (C57BL/6J) were studied using a high-frequency ultrasound system (40 MHz). Lumen area and blood flow waveforms were obtained from the LCCA and used to calculate pulse-wave velocity, input impedance, and reflection amplitude and transit time under both normocapnic and hypercapnic (5% CO2) ventilation. With hypercapnia, vascular resistance was observed to decrease by 87%±12%. Although the modulus of input impedance was unchanged with hypercapnia, a phase decrease indicative of increased total arterial compliance was observed at low harmonics together with an increased reflection coefficient in both the time (0.57±0.08 versus 0.68±0.08, P=0.04) and frequency domains (0.62±0.08 versus 0.73±0.06, P=0.02). Interestingly, the majority of LCCA blood flow was found to pass into the internal carotid artery (range=76% to 90%, N=3), suggesting that hemodynamic measurements in this vessel are a good metric for intracerebral reactivity in mouse.

scholarly journals Changes in the microcirculation of the oral mucosa in post-COVID-19 patients not receiving anti-coagulant therapy

2022 ◽  
Vol 20 (4) ◽  
pp. 95-100
Author(s):  
M. V. Chubarnova ◽  
A. B. Davydov ◽  
V. A. Esin ◽  
O. B. Davydova ◽  
I. O. Kostin
Keyword(s):  
Blood Flow ◽  
Oral Mucosa ◽  
High Frequency ◽  
Control Group ◽  
High Frequency Ultrasound ◽  
Flow Rates ◽  
Mean Values ◽  
Coronavirus Infection ◽  
The Mean ◽  
Frequency Ultrasound

Introduction. The outbreak of a new coronavirus infection has become a challenge for the global health system. The COVID-19 infection is directly related to various disorders of the cardiovascular system, including the microcirculatory bed, caused by thrombotic events and deteriorations of blood rheology. Aims. The paper reports on the results of a study of Doppler sonographic parameters changes in patients with a novel coronavirus infection over the past 6 months. Materials and methods. We assessed the oral mucosa microcirculation in three segments using the high-frequency ultrasound dopple-rography. Results. We recorded the linear and volumetric blood flow rates and the Gosling and Purselo indexes in the course of our work. When comparing the obtained average statistical parameters of blood flow velocity, the linear and volumetric blood flow rates in patients of both groups were found to be lain in the same range and the mean values of Vas, Vam, Qas were equal. The mean values of the Purselo resistance index were closer to 1,0 in patients with COVID-19, and the values of the Gosling pulsation index (PI) were on average 53.3 % higher than in the control group. Conclusion. We evaluated the screening capabilities and potential of high-frequency ultrasound dopplerography for use in patients of different age groups and different somatic status.

scholarly journals Effectiveness of Deep Hyperthermia Combined with Dynamic Traction in the Treatment of Knee Osteoarthritis

2021 ◽  
Author(s):  
Lichun Wang ◽  
Liu Lv ◽  
Hongli Zhang ◽  
Hua Chen ◽  
Fei Li ◽  
...  
Keyword(s):  
Blood Flow ◽  
Knee Osteoarthritis ◽  
High Frequency ◽  
Post Treatment ◽  
High Frequency Ultrasound ◽  
Flow Signal ◽  
Joint Cavity ◽  
Blood Flow Signal ◽  
Deep Hyperthermia ◽  
Frequency Ultrasound

Abstract Background: Different treatments with varying clinical efficacies have been applied to treat knee osteoarthritis (KOA). This study observes the effectiveness of deep hyperthermia combined with dynamic traction in KOA treatment. Methods: Deep hyperthermia and dynamic traction was administered to 60 patients with KOA. The pretreatment and 20- and 40-day post-treatment visual analog scale (VAS) and Lysholm score, knee joint cavity effusion, synovium thickness, and synovial blood flow signal (by high-frequency ultrasound) of the patients were recorded. The pretreatment and 20- and 40-day post-treatment Lysholm scores were 47.17 ± 5.07, 63.22 ± 3.44, and 81.98 ± 3.30 (P < 0.001), respectively. Results: The pretreatment and 20- and 40-day post-treatment VAS scores were 5.67 ± 0.91, 2.92 ± 0.81, and 0.60 ± 0.72 (P < 0.001), respectively. The pretreatment and 20- and 40-day post-treatment articular effusion was 5.41 ± 0.46 mm, 4.34 ± 0.34 mm, and 2.32 ± 0.32 mm (P < 0.001), respectively. The pretreatment and 20- and 40-day post-treatment synovial thickness was 3.44 ± 0.31 mm, 2.79 ± 0.15 mm, and 2.32 ± 0.32 mm (P < 0.001), respectively. The pretreatment and 20- and 40-day post-treatment grades of synovial blood flow signal exhibited a significant difference (P < 0.001). Conclusion: Deep hyperthermia combined with dynamic traction can significantly improve the clinical symptoms and pain degree in KOA, reduce joint cavity effusion, synovium thickness, and internal blood flow, and the effect improves with time. The changes in soft tissues observed by high-frequency ultrasound are reliable and consistent with clinical signs.

Clinical Research of Thyroid Imaging Reporting and Data System Classification Combined with Color-Doppler Blood-Flow Parameters in Diagnosis of Benign and Malignant Thyroid Nodules

2020 ◽  
Vol 10 (7) ◽  
pp. 1564-1569
Author(s):  
Hongzhu Wang ◽  
Da Yu ◽  
Kunzhong Bao
Keyword(s):  
Blood Flow ◽  
High Frequency ◽  
Thyroid Nodules ◽  
Color Doppler ◽  
Resistance Index ◽  
Data System ◽  
High Frequency Ultrasound ◽  
Thyroid Imaging ◽  
Flow Parameters ◽  
Frequency Ultrasound

In order to investigate the characteristics of high-frequency ultrasound for the patients with thyroid nodules (TN), and we use the Thyroid Imaging Reporting And Data System (TI-RADS) to classify all the TN. Combined TIRADS classification with the features of color Doppler ultrasound and Doppler blood flow parameters for each nodule, we tried to diagnose TN between benign and malignant nodules so as to provide clinical physicians a more appropriate method and decision-making strategy for patients with of TN by ultrasound findings. The pulse Doppler technique was used to measure the peak systolic velocity (PSV) and resistance index (RI) of the blood flow within the nodule or closely around. The final pathology results were compared with all the ultrasound test. The diagnostic coincidence rates for B&M-TN were statistically compared by single two-dimensional ultrasound or by single color Doppler flow imaging or by combined technique of both. It can be seen that the combination strategy can optimize the coincidence rate of clinical diagnosis of B&M-TN. Therefore, the differential diagnosis of TN by high-frequency ultrasound TI-RADS classification combined with color Doppler blood flow parameters deserves our attention and further study.

A Method for Gray-Scale Imaging of Blood Flow Using High-Frequency Ultrasound

2017 ◽  
Vol 40 (1) ◽  
pp. 3-14
Author(s):  
Jun Yang ◽  
Chao Pang ◽  
Xue-Dong Song ◽  
Xuan Gao
Keyword(s):  
Blood Flow ◽  
High Frequency ◽  
Single Pulse ◽  
Frequency Range ◽  
High Frequency Ultrasound ◽  
Blood Flow Imaging ◽  
Blood Flow Signal ◽  
Flow Information ◽  
Blood Imaging ◽  
Frequency Ultrasound

This paper presents a new method that complements current techniques available in the high-frequency blood imaging field. A comprehensive scattering model was established to determine the feasibility and frequency range of the blood flow imaging of superficial organs and tissues using high-frequency ultrasound. The transmitting and receiving modes and an algorithm were designed to obtain blood flow information based on differentiation between tissues and blood flow. The system was created and tested first with a model that simulates blood flow and was then used on human tissue. A fine-scale image of a blood vessel could be obtained with this system. Moreover, this method can obtain weak blood flow signal using single pulse rather than the traditional pulse-code method and maintains a high resolution that can be matched to high-frequency structural imaging. This study provides a reliable method for further applications related to diagnoses of superficial organs.

Optimization of real-time high-frequency ultrasound for blood flow imaging in the microcirculation

2001 ◽  
Author(s):  
Dustin E. Kruse ◽  
Jerome J. Mai ◽  
Ronald H. Silverman ◽  
Michael F. Insana ◽  
D. J. Coleman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
High Frequency ◽  
Flow Imaging ◽  
High Frequency Ultrasound ◽  
Blood Flow Imaging ◽  
Frequency Ultrasound
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