To develop a new noninvasive approach to quantify left ventricular (LV) pressures using subharmonic emissions from microbubbles, an ultrasound scanner was used in pulse inversion grayscale mode; unprocessed radiofrequency data were obtained with pulsed wave Doppler from the aorta and/or LV during Sonazoid infusion. Subharmonic data (in dB) were extracted and processed. Calibration factor (mm Hg/dB) from the aortic pressure was used to estimate LV pressures. Errors ranged from 0.19 to 2.50 mm Hg when estimating pressures using the aortic calibration factor, and were higher (0.64 to 8.98 mm Hg) using a mean aortic calibration factor. Subharmonic emissions from ultrasound contrast agents have the potential to noninvasively monitor LV pressures.
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http://dx.doi.org/10.1016/j.jcmg.2011.08.017 | DOI Listing |
Ultrasonics
December 2024
Department of Biomedical Engineering, School of Life Health Information Science and Engineering, Chongqing University of Posts and Telecommunications, Chongqing, People's Republic of China; Postdoctoral Workstation of Chongqing General Hospital, Chongqing, People's Republic of China. Electronic address:
Submicron ultrasound contrast agents hold great potential to extend the bubble-mediated theranostics beyond the vasculature, but their acoustic response and the interaction effects between them remain poorly understood. This study set out to numerically examine the interaction effects on the subharmonic oscillations of nanobubbles and the resultant acoustic emissions under subharmonic resonance conditions. Results showed that a negative correlation between bubble size and subharmonic resonance frequency is readily obtained from the radius response curves.
View Article and Find Full Text PDFUltrason Sonochem
October 2024
Department of Radiology, University of Michigan, Ann Arbor, MI, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA. Electronic address:
Acoustic droplet vaporization (ADV) offers a dynamic approach for generating bubbles on demand, presenting new possibilities in biomedical applications. Although ADV has been investigated in various biomedical applications, its potential in tissue characterization remains unexplored. Here, we investigated the effects of surrounding media on the radial dynamics and acoustic emissions of ADV bubbles using theoretical and experimental methodologies.
View Article and Find Full Text PDFJ Control Release
August 2024
Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States of America; Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, United States of America.
Purpose: We report our experience disrupting the blood-brain barrier (BBB) to improve drug delivery in glioblastoma patients receiving temozolomide chemotherapy. The goals of this retrospective analysis were to compare MRI-based measures of BBB disruption and vascular damage to the exposure levels, acoustic emissions data, and acoustic simulations. We also simulated the cavitation detectors.
View Article and Find Full Text PDFUltrason Sonochem
March 2024
School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:
The use of the subharmonic signal from microbubbles exposed to ultrasound is a promising safe and cost-effective approach for the non-invasive measurement of blood pressure. Achieving a high sensitivity of the subharmonic amplitude to the ambient overpressure is crucial for clinical applications. However, currently used microbubbles have a wide size distribution and diverse shell properties.
View Article and Find Full Text PDFMed Phys
November 2023
Department of Ultrasound, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Background: Stroke is closely related to carotid atherosclerotic plaques, which tend to occur in specific parts of the arteries, especially at the bifurcations, and are considered to be caused by biomechanical factors. Quantitative analysis of hemodynamic stress characteristics of the carotid sinus in vivo provides a mechanical basis for the development of atherosclerotic plaque in the carotid sinus. Previous studies found that ultrasound (US) contrast agent microbubbles would vibrate nonlinearly under the excitation of sound pressure, generating subharmonics (transmission fundamental frequency, i.
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