Arterial Thrombus Dissolution In Vivo Using a Transducer-Tipped, High-Frequency Ultrasound Catheter and Local Low-Dose Urokinase Delivery

Purpose: To examine the hypothesis that a transducer-tipped high-frequency ultrasound drug-delivery catheter may augment the thrombolytic effects of locally delivered low-dose urokinase and result in improved recanalization rates and reduced residual thrombotic burden. Methods: Thrombi were induced in situ bilaterally in 5- to 6-cm-long segments of the superficial femoral arteries in 9 dogs by intraluminal thermal damage and injection of thrombin. A transducer-tipped high-frequency local drug-delivery catheter was applied at 1.1 MHz and 0.6 W for 60 minutes to one superficial femoral artery segment, and an identical catheter with an inactivated ultrasound transducer was used to treat the contralateral control segment. Urokinase (5000 IU/kg) was delivered bilaterally into the thrombi during the treatment interval. Results: Angiography documented TIMI grade 2 or 3 flow in 9 (100%) segments in the ultrasound-treated group versus 6 (67%) of the controls (no ultrasound) (p = 0.058). Angiographically detected distal embolization was found in 2 ultrasound-treated segments compared with 5 controls (p = 0.02). Protruding or occlusive thrombi were seen angioscopically in 8 (89%) control segments but in only 1 (11%) of the ultrasound-treated arteries (p < 0.001). By histopathology, 7 (78%) segments in the control group had occlusive thrombi, whereas only 3 nonocclusive thrombi were found in the ultrasound-treatment group (p < 0.001). Conclusions: Catheter-delivered high-frequency ultrasound and local low-dose urokinase infusion is efficacious for the treatment of acute thrombotic occlusions as evaluated by angiography, angioscopy, and histopathology.

Download Full-text

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

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.37.suppl_1.245 ◽

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.

Download Full-text

Ultra high frequency ultrasound: a promising technique to visualize pelvic floor meshes in vivo

Ultrasound in Obstetrics and Gynecology ◽

10.1002/uog.22137 ◽

2020 ◽

Author(s):

A. W. Kastelein ◽

B. C. de Graaf ◽

Y. P. Latul ◽

K. W. J. Verhorstert ◽

J. Holthof ◽

...

Keyword(s):

Pelvic Floor ◽

High Frequency ◽

High Frequency Ultrasound ◽

Promising Technique ◽

Ultra High Frequency ◽

Frequency Ultrasound

Download Full-text

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

Ultrasonics ◽

10.1016/j.ultras.2008.08.005 ◽

2009 ◽

Vol 49 (2) ◽

pp. 226-230 ◽

Cited By ~ 25

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

Download Full-text

Use of weekly, low dose, high frequency ultrasound for hard to heal venous leg ulcers: the VenUS III randomised controlled trial

Yearbook of Sports Medicine ◽

10.1016/j.yspm.2011.08.032 ◽

2012 ◽

Vol 2012 ◽

pp. 109-111

Author(s):

D.E. Feldman

Keyword(s):

Randomised Controlled Trial ◽

High Frequency ◽

Low Dose ◽

Controlled Trial ◽

Leg Ulcers ◽

High Frequency Ultrasound ◽

Venous Leg Ulcers ◽

Randomised Controlled ◽

Frequency Ultrasound

Download Full-text

In vitro and in vivo high‐frequency ultrasound response of microbubbles

The Journal of the Acoustical Society of America ◽

10.1121/1.4786921 ◽

2006 ◽

Vol 119 (5) ◽

pp. 3438-3438

Author(s):

Orlando Aristizábal ◽

Daniel H. Turnbull ◽

Jeffrey A. Ketterling

Keyword(s):

High Frequency ◽

High Frequency Ultrasound ◽

Frequency Ultrasound

Download Full-text

Comparison of optical coherence tomography and high frequency ultrasound imaging in mice for the assessment of skin morphology and intradermal volumes

Scientific Reports ◽

10.1038/s41598-019-50104-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Kornelia Schuetzenberger ◽

Martin Pfister ◽

Alina Messner ◽

Vanessa Froehlich ◽

Gerhard Garhoefer ◽

...

Keyword(s):

Optical Coherence Tomography ◽

High Frequency ◽

Ex Vivo ◽

Clinical Settings ◽

Optical Coherence ◽

High Frequency Ultrasound ◽

Skin Morphology ◽

Frequency Ultrasound ◽

Good Agreement

Abstract Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS), two established imaging modalities in the field of dermatology, were evaluated and compared regarding their applicability for visualization of skin tissue morphology and quantification of murine intradermal structures. The accuracy and reproducibility of both methods were assessed ex vivo and in vivo using a standardized model for intradermal volumes based on injected soft tissue fillers. OCT revealed greater detail in skin morphology, allowing for detection of single layers due to the superior resolution. Volumetric data measured by OCT (7.9 ± 0.3 μl) and HFUS (7.7 ± 0.5 μl) were in good agreement and revealed a high accuracy when compared to the injected volume of 7.98 ± 0.8 µl. In vivo, OCT provided a higher precision (relative SD: 26% OCT vs. 42% HFUS) for the quantification of intradermal structures, whereas HFUS offered increased penetration depth enabling the visualization of deeper structures. A combination of both imaging technologies might be valuable for tumor assessments or other dermal pathologies in clinical settings.

Download Full-text

Monitoring of Adult Zebrafish Heart Regeneration Using High-Frequency Ultrasound Spectral Doppler and Nakagami Imaging

Sensors ◽

10.3390/s19194094 ◽

2019 ◽

Vol 19 (19) ◽

pp. 4094 ◽

Cited By ~ 1

Author(s):

Sunmi Yeo ◽

Changhan Yoon ◽

Ching-Ling Lien ◽

Tai-Kyong Song ◽

K. Kirk Shung

Keyword(s):

High Frequency ◽

Doppler Imaging ◽

Adult Zebrafish ◽

High Frequency Ultrasound ◽

In Vivo Experiments ◽

Longitudinal Measurements ◽

Array Transducer ◽

Spectral Doppler ◽

Frequency Ultrasound

This paper reports the feasibility of Nakagami imaging in monitoring the regeneration process of zebrafish hearts in a noninvasive manner. In addition, spectral Doppler waveforms that are typically used to access the diastolic function were measured to validate the performance of Nakagami imaging. A 30-MHz high-frequency ultrasound array transducer was used to acquire backscattered echo signal for spectral Doppler and Nakagami imaging. The performances of both methods were validated with flow and tissue-mimicking phantom experiments. For in vivo experiments, both spectral Doppler and Nakagami imaging were simultaneously obtained from adult zebrafish with amputated hearts. Longitudinal measurements were performed for five zebrafish. From the experiments, the E/A ratio measured using spectral Doppler imaging increased at 3 days post-amputation (3 dpa) and then decreased to the value before amputation, which were consistent with previous studies. Similar results were obtained from the Nakagami imaging where the Nakagami parameter value increased at 3 dpa and decreased to its original value. These results suggested that the Nakagami and spectral Doppler imaging would be useful techniques in monitoring the regeneration of heart or tissues.

Download Full-text