scholarly journals Acoustically-Stimulated Nanobubbles: Opportunities in Medical Ultrasound Imaging and Therapy

2021 ◽  
Vol 9 ◽  
Author(s):  
Brandon Helfield ◽  
Yiran Zou ◽  
Naomi Matsuura
Keyword(s):  
Contrast Agents ◽  
Ultrasound Contrast Agent ◽  
Ultrasound Contrast Agents ◽  
Medical Ultrasound ◽  
Specific Therapy ◽  
Medical Ultrasound Imaging ◽  
Non Invasive ◽  
Ultrasound Contrast ◽  
Scaling Down

Medical ultrasound is one of the most widely used imaging modalities worldwide. Microbubbles, typically ~1–8 μm in diameter, are ultrasound contrast agents confined to the vasculature due to their size. Microbubbles have broadened the scope of medical ultrasound, permitting real-time imaging of the microvasculature for blood flow assessment, molecular imaging, and even non-invasive site-specific therapy. Recently, there has been increasing interest in developing submicron, “nanoscale” agents to extend the utility of medical ultrasound. In this review, we discuss the development of lipid-encapsulated, acoustically responsive, nanobubbles (~200–800 nm in diameter), a next-generation ultrasound contrast agent. First, medical ultrasound and bubble-based contrast agents are introduced, followed by the advantages of scaling down bubble size from an acoustic and biological viewpoint. Next, we present how lipid-encapsulated nanobubbles can be developed toward meeting clinically meaningful endpoints, from agent synthesis and characterization to in vivo considerations. Finally, future opportunities of nanobubbles for advanced applications in ultrasound diagnostic and therapeutic medicine are proposed.

scholarly journals Molecular imaging of orthotopic prostate cancer with nanobubble ultrasound contrast agents targeted to PSMA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Wang ◽  
Al Christopher De Leon ◽  
Reshani Perera ◽  
Eric Abenojar ◽  
Ramamurthy Gopalakrishnan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Ultrasound Imaging ◽  
Prostate Gland ◽  
Ultrasound Contrast Agent ◽  
Tumor Model ◽  
Focal Therapy ◽  
Ultrasound Contrast Agents ◽  
Time Intensity Curve ◽  
Ultrasound Contrast

AbstractUltrasound imaging is routinely used to guide prostate biopsies, yet delineation of tumors within the prostate gland is extremely challenging, even with microbubble (MB) contrast. A more effective ultrasound protocol is needed that can effectively localize malignancies for targeted biopsy or aid in patient selection and treatment planning for organ-sparing focal therapy. This study focused on evaluating the application of a novel nanobubble ultrasound contrast agent targeted to the prostate specific membrane antigen (PSMA-targeted NBs) in ultrasound imaging of prostate cancer (PCa) in vivo using a clinically relevant orthotopic tumor model in nude mice. Our results demonstrated that PSMA-targeted NBs had increased extravasation and retention in PSMA-expressing orthotopic mouse tumors. These processes are reflected in significantly different time intensity curve (TIC) and several kinetic parameters for targeted versus non-targeted NBs or LUMASON MBs. These, may in turn, lead to improved image-based detection and diagnosis of PCa in the future.

scholarly journals Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
John R. Eisenbrey ◽  
Anush Sridharan ◽  
Ji-Bin Liu ◽  
Flemming Forsberg
Keyword(s):  
Contrast Agents ◽  
Tumor Imaging ◽  
Three Dimensional ◽  
Ultrasound Contrast Agents ◽  
Surrounding Tissue ◽  
Contrast Enhanced Ultrasound ◽  
Ultrasound Contrast ◽  
Contrast Enhanced ◽  
Subharmonic Response

Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imagingin vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

Stabilized bubbles in the body: pressure-radius relationships and the limits to stabilization

1997 ◽  
Vol 82 (6) ◽  
pp. 2045-2053 ◽  
Author(s):  
Hugh D. Van Liew ◽  
Soumya Raychaudhuri
Keyword(s):  
Contrast Agents ◽  
Conceptual Framework ◽  
Bubble Radius ◽  
Ultrasonic Imaging ◽  
Ultrasound Contrast Agents ◽  
The Body ◽  
Strong Growth ◽  
Ultrasound Contrast ◽  
Practical Usefulness

Van Liew, Hugh D., and Soumya Raychaudhuri. Stabilized bubbles in the body: pressure-radius relationships and the limits to stabilization. J. Appl. Physiol.82(6): 2045–2053, 1997.—We previously outlined the fundamental principles that govern behavior of stabilized bubbles, such as the microbubbles being put forward as ultrasound contrast agents. Our present goals are to develop the idea that there are limits to the stabilization and to provide a conceptual framework for comparison of bubbles stabilized by different mechanisms. Gases diffuse in or out of stabilized bubbles in a limited and reversible manner in response to changes in the environment, but strong growth influences will cause the bubbles to cross a threshold into uncontrolled growth. Also, bubbles stabilized by mechanical structures will be destroyed if outside influences bring them below a critical small size. The in vivo behavior of different kinds of stabilized bubbles can be compared by using plots of bubble radius as a function of forces that affect diffusion of gases in or out of the bubble. The two ends of the plot are the limits for unstabilized growth and destruction; these and the curve’s slope predict the bubble’s practical usefulness for ultrasonic imaging or O2 carriage to tissues.

In vivo observation of urinary reflux using ultrasound contrast agents

1993 ◽  
Vol 28 (12) ◽  
pp. 1182 ◽  
Author(s):  
J. A. Ivey ◽  
J. B. Fowlkes ◽  
E. A. Gardner ◽  
W. F.J. Feitz ◽  
D. A. Bloom ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Ultrasound Contrast Agents ◽  
Ultrasound Contrast

scholarly journals Subharmonic microbubble emissions for noninvasively tracking right ventricular pressures

2012 ◽  
Vol 303 (1) ◽  
pp. H126-H132 ◽  
Author(s):  
Jaydev K. Dave ◽  
Valgerdur G. Halldorsdottir ◽  
John R. Eisenbrey ◽  
Joel S. Raichlen ◽  
Ji-Bin Liu ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Contrast Agents ◽  
Acoustic Emissions ◽  
Right Heart Catheterization ◽  
Ultrasound Contrast Agents ◽  
Heart Catheterization ◽  
Ultrasound Contrast ◽  
Individual Calibration ◽  
The Individual

Right heart catheterization is often required to monitor intra-cardiac pressures in a number of disease states. Ultrasound contrast agents can produce pressure modulated subharmonic emissions that may be used to estimate right ventricular (RV) pressures. A technique based on subharmonic acoustic emissions from ultrasound contrast agents to track RV pressures noninvasively has been developed and its clinical potential evaluated. The subharmonic signals were obtained from the aorta, RV, and right atrium (RA) of five anesthetized closed-chest mongrel dogs using a SonixRP ultrasound scanner and PA4-2 phased array. Simultaneous pressure measurements were obtained using a 5-French solid state micromanometer tipped catheter. Initially, aortic subharmonic signals and systemic blood pressures were used to obtain a calibration factor in units of millimeters of mercury per decibel. This factor was combined with RA pressures (that can be obtained noninvasively) and the acoustic data from the RV to obtain RV pressure values. The individual calibration factors ranged from −2.0 to −4.0 mmHg/dB. The subharmonic signals tracked transient changes in the RV pressures within an error of 0.6 mmHg. Relative to the catheter pressures, the mean errors in estimating RV peak systolic and minimum diastolic pressures, and RV relaxation [isovolumic negative derivative of change in pressure over time (−dP/d t)] by use of the subharmonic signals, were −2.3 mmHg, −0.8 mmHg, and 2.9 mmHg/s, respectively. Overall, acoustic estimates of RV peak systolic and minimum diastolic pressures and RV relaxation were within 3.4 mmHg, 1.8 mmHg, and 5.9 mmHg/s, respectively, of the measured pressures. This pilot study demonstrates that subharmonic emissions from ultrasound contrast agents have the potential to noninvasively track in vivo RV pressures with errors below 3.5 mmHg.

scholarly journals Non-invasive estimation of blood pressure using ultrasound contrast agents

2010 ◽  
Vol 3 (1) ◽  
pp. 245-253 ◽  
Author(s):  
Klaus Scheldrup Andersen ◽  
Jørgen Arendt Jensen
Keyword(s):  
Blood Pressure ◽  
Contrast Agents ◽  
Ultrasound Contrast Agents ◽  
Non Invasive ◽  
Ultrasound Contrast

Characteristics and Echogenicity of Clinical Ultrasound Contrast Agents: An In Vitro and In Vivo Comparison Study

2017 ◽  
Vol 36 (5) ◽  
pp. 941-953 ◽  
Author(s):  
Jean-Marc Hyvelin ◽  
Emmanuel Gaud ◽  
Maria Costa ◽  
Alexandre Helbert ◽  
Philippe Bussat ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Ultrasound Contrast Agents ◽  
Comparison Study ◽  
Ultrasound Contrast
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