High frame-rate ultrasound RF data acquisition has been proved to be critical for novel cardiovascular imaging techniques, such as high-precision myocardial elastography, pulse wave imaging (PWI), and electromechanical wave imaging (EWI). To overcome the frame-rate limitations on standard clinical ultrasound systems, we developed an automated method for… (More)
The therapeutic efficacy of neurological agents is severely limited, because large compounds do not cross the blood-brain barrier (BBB). Focused ultrasound (FUS) sonication in the presence of microbubbles has been shown to temporarily open the BBB, allowing systemically administered agents into the brain. Until now, polydispersed microbubbles (1-10 microm… (More)
Focused ultrasound (FUS) is hereby shown to noninvasively and selectively deliver compounds at pharmacologically relevant molecular weights through the opened blood-brain barrier (BBB). A complete examination on the size of the FUS-induced BBB opening, the spatial distribution of the delivered agents and its dependence on the agent's molecular weight were… (More)
The spatio-temporal nature of focused ultrasound-induced blood-brain barrier (BBB) opening as a brain drug delivery method was investigated in Alzheimer's disease model mice. The left hippocampus of transgenic (APP/PS1, n = 3) and nontransgenic (n = 3) mice was sonicated (frequency: 1.525 MHz, peak-negative pressure: 600 kPa, pulse length: 20 ms, duty… (More)
— Vascular diseases (e.g., abdominal aortic aneurysm or, AAA) lead to changes in the regional aortic wall mechanical properties. Pulse-Wave Imaging (PWI) was previously developed by our group to map the pulse-wave propagation along the abdominal aorta of mice in vivo. In this study, the feasibility of PWI with real-time scanning is shown in human abdominal… (More)
—In this paper, the requirement and optimization of the frame rate for myocardial elastography was investigated in normal mice and humans in vivo. Using a retrospective electrocardiogram (ECG) gating technique, the highest frame rate was 8 kHz and 481 Hz, respectively. Axial displacement and strain of myocardium were estimated using an RF speckle tracking… (More)
— The delivery of gadolinium through the ultrasound-induced blood-brain barrier (BBB) openings of mice was investigated. The left hippocampus of mice (n=13) was sonicated molecular weight were more uniformly deposited throughout the hippocampus than larger molecules.
— The objective of this study is to validate two-dimensional (2D) myocardial elastography estimates in canine hearts in vivo against direct sonomicrometry measurements at variable levels of myocardial ischemia induced by the occlusion of the left anterior descending (LAD) coronary artery. in radial strain between the two methods was found from the… (More)