We have previously reported that ultrastable lipid-coated microbubbles make a suitable ultrasonic contrast agent in the brain, causing increased intensity of echoes that persists for many hours. We showed that intravenously administered lipid-coated microbubbles accumulate selectively in rat brain gliomas with echogenicity enhancement for up to 1 hour, allowing visualization of the growing lesions 40% (2 days) earlier than can be seen without contrast. This work is a detailed evaluation of the accumulation of the lipid-coated microbubbles in tumor and the effect of the bubbles on the echogenicity of insonified tumors. Using a lipid-specific stain, we measured and characterized the distribution of the bubbles in the brain and tumor. We showed that on the scan, the enhancement of the tumor is accompanied by a change in the signal-to-noise ratio of the echoes from the tumor. We identified characteristic textural changes associated with contrast-enhanced tumor using spectral analysis.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1097/00004424-199201000-00003 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effect of Lipid Composition and Stirring Dynamics on Oxygen Microbubble Stability and Oxygen Release.
Langmuir
January 2025
Biomedical Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States.
Lipid-coated oxygen microbubbles (OMBs) are being investigated for biomedical applications to alleviate hypoxia such as systemic oxygenation and image-guided radiosensitization therapy. Additionally, they hold potential for boarder application as oxygen carriers beyond the biomedical filed. Understanding the stability and oxygen release properties of OMBs in dynamic aqueous environments is critical for these applications.
View Article and Find Full Text PDFExperimental investigation on the effect of concentration on the resonance frequency of lipid coated ultrasonically excited microbubbles.
Ultrason Sonochem
January 2025
Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario, Canada; Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between St. Michael's Hospital and Toronto Metropolitan University, 209 Victoria St, Toronto, Ontario, Canada.
This study presents an experimental investigation of the influence of MB concentration on the resonance frequency of lipid-coated microbubbles (MBs). Expanding on theoretical models and numerical simulations from previous research, this work experimentally investigates the effect of MB size on the rate of resonance frequency increase with concentration, a phenomenon observed across MBs with two different lipid compositions: propylene glycol (PG) and propylene glycol and glycerol (PGG). Employing a custom-designed ultrasound attenuation measurement setup, we measured the frequency-dependent attenuation of MBs, isolating MBs based on size to generate distinct monodisperse sub-populations for analysis.
View Article and Find Full Text PDFBehavior of Microbubbles on Air-Aqueous Interfaces.
Langmuir
November 2024
Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford OX3 7LD, U.K.
Animal-derived lung surfactants have saved millions of lives of preterm neonates with neonatal Respiratory Distress Syndrome (nRDS). However, a replacement for animal-derived lung surfactants has been sought for decades due to its high manufacturing cost, inaccessibility in low-income countries, and failure to show efficacy when nebulized. This study investigated the use of lipid-coated microbubbles as potential replacements for exogenous lung surfactants.
View Article and Find Full Text PDFDeciphering the hydrodynamics of lipid-coated microbubble sonoluminescence for sonodynamic therapy.
Ultrason Sonochem
December 2024
Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089, United States; Mork Family Department of Chemical Engineering and Material Science, University of Southern California, Los Angeles, CA 90089, United States; Alfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, United States.
Sonodynamic therapy (SDT) is a minimally invasive targeted cancer therapy that uses focused low-intensity ultrasound (<10 MPa, <10 W/cm) to activate sonosensitizer drugs. Once activated, these chemical compounds generate reactive oxygen species (ROS) to damage and kill cancer cells. A Phase I clinical trial has shown promising results for treating glioblastoma with SDT.
View Article and Find Full Text PDFAnalysis of Microbubble-Blood cell system Oscillation/Cavitation influenced by ultrasound Forces: Conjugate applications of FEM and LBM.
Ultrason Sonochem
August 2024
Department of Mechanical Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Sonoporation is a non-invasive method that uses ultrasound for drug and gene delivery for therapeutic purposes. Here, both Finite Element Method (FEM) and Lattice Boltzmann Method (LBM) are applied to study the interaction physics of microbubble oscillation and collapse near flexible tissue. After validating the Finite Element Method with the nonlinear excited lipid-coated microbubble as well as the Lattice Boltzmann Method with experimental results, we have studied the behavior of a three-dimensional compressible microbubble in the vicinity of tissue.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!