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.

Abstract 245: Non-Invasive in vivo Assessment of the Re-Endothelialization Process Using Ultrasound Biomicroscopy in the Rat Carotid Artery Balloon Injury Model

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Samuel Röhl ◽  
Linnea Eriksson ◽  
Robert Saxelin ◽  
Mariette Lengquist ◽  
Kenneth Caidahl ◽  
...  
Keyword(s):  
Carotid Artery ◽  
High Frequency ◽  
Ultrasound Biomicroscopy ◽  
Blue Dye ◽  
High Frequency Ultrasound ◽  
Balloon Injury ◽  
En Face ◽  
In Vivo Assessment ◽  
Frequency Ultrasound

Objective: Ultrasound BioMicroscopy (UBM), or high-frequency ultrasound, is a novel technique used for assessment of anatomy and physiology small research animals. In this study, we evaluate the UBM assessment of the re-endothelialization process following denudation of the carotid artery in rats. Methods: Ultrasound BioMicroscopy data from three different experiments were analyzed. A total of 66 rats of three different strains (Sprague-Dawley, Wistar and Goto-Kakizaki) were included in this study. All animals were subjected to common carotid artery balloon injury and examined with UBM 2 and 4 weeks after injury. Re-endothelialization in UBM was measured as the length from the carotid bifurcation to the distal edge of the intimal hyperplasia. En face staining with Evans-blue dye was performed upon euthanization at 4 weeks after injury followed by tissue harvest for morphological and immunohistochemical evaluation. Results: A significant correlation (Spearman r=0.63,p<0.0001) and an agreement according to Bland-Altman test was identified when comparing all measurements of re-endothelialization in high frequency ultrasound and en face staining. Analysis by animal strain revealed a similar pattern and a significant growth in re-endothelialization length measured in UBM from 2 to 4 weeks could be identified. Immunohistochemical staining for von Willebrand factor confirmed the presence of endothelium in the areas detected as re-endothelialized by the ultrasound assessment. Conclusion: Ultrasound BioMicroscopy can be used for longitudinal in vivo assessment of the re-endothelialization following arterial injury in rats.

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 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.

Abstract 310: High Frequency Ultrasound Reveals Dobutamine Increases Murine Aortic Strain

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Amelia R Adelsperger ◽  
Paige Castle ◽  
Joan M Greve ◽  
Craig J Goergen
Keyword(s):  
Heart Rate ◽  
Carotid Artery ◽  
High Frequency ◽  
The Body ◽  
Aortic Aneurysms ◽  
Dobutamine Infusion ◽  
Infrarenal Aorta ◽  
High Frequency Ultrasound ◽  
Suprarenal Aorta ◽  
Frequency Ultrasound

Dobutamine increases heart rate and cardiac output, similar to the effects the sympathetic nervous system has on the body during exercise. This makes dobutamine an excellent surrogate for exercise, and it is often administered during stress tests. The purpose of this study was to quantify changes in arterial strain using in vivo high frequency ultrasound in order to better understand the effects of dobutamine on vascular dynamics. Here, C57BL/6 mice were infused with 40 μg/min/kg of dobutamine at a flow rate of 0.002 mL/min via a tail vein catheter (n=3; 19 weeks old, 31 ± 2.0 g). Ultrasound images of the suprarenal aorta, infrarenal aorta, iliac arteries, and carotid artery were acquired before the infusion of dobutamine (baseline) and again after the heart rate had plateaued during the infusion using B- and M-Modes images in both short and long axis. These mice showed an average heart rate increase of 76±18.7 bpm roughly 20 minutes after the start of the dobutamine infusion. Green-Lagrangian circumferential cyclic strain, calculated from arterial diameters in systole (maximum, dashed) and diastole (minimum, solid), increased throughout the vasculature after infusion. The suprarenal aorta increased from 22.5±1.3% to 41.9±2.4%, while the infrarenal aorta increased from 21.2±2.5% to 38.0±1.7%. The iliac artery increased from 22.4±2.9% to 42.0±2.7%, and the carotid artery increased from 26.0±2.3% to 43.5±5.2%. The average strain for all four locations increased from 23.0±2.1% (A) to 41.4±2.4% (B), representing a 79.6% increase from baseline. These results suggest that high frequency ultrasound is capable of capturing rapid changes in vascular dynamics due to dobutamine infusion. The effects of dobutamine on these healthy vessels can be used as a baseline for future studies that investigate murine disease models including advanced atherosclerosis and abdominal aortic aneurysms.

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.

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