Passive cavitation detection has been an instrumental technique for measuring dynamics, elucidating concomitant bioeffects, and guiding ultrasound therapies. Recently, techniques have developed to create images of activity provide investigators with a more complete set information. These use arrays record subsequently beamform received emissions, rather than processing emissions on single-element transducer. In this paper, the methods performing frequency-domain delay, sum, integrate passive...

The mechanical index (MI) was formulated to gauge the likelihood of adverse bioeffects from inertial cavitation. However, MI formulation did not consider bubble activity stable This type can be readily nucleated ultrasound contrast agents (UCAs) and has potential promote beneficial bioeffects. Here, presence cavitation is determined numerically by tracking onset subharmonic oscillations within a population bubbles for frequencies up 7 MHz peak rarefactional pressures 3 MPa. In addition,...

Histotripsy, a form of therapeutic ultrasound that uses the mechanical action microbubble clouds for tissue ablation, is under development to treat chronic deep vein thrombosis (DVT). We hypothesize combining thrombolytic agents with histotripsy will enhance clot lysis. Recombinant plasminogen activator (rt-PA) and rt-PA-loaded echogenic liposomes entrain octafluoropropane microbubbles (OFP t-ELIP) were used in combination highly shocked pulses. Fully retracted porcine venous clots, similar...

Ultrasound contrast agents (UCAs) have the potential to nucleate cavitation and promote both beneficial deleterious bioeffects in vivo. Previous studies elucidated pulse-duration-dependent pressure amplitude threshold for rapid loss of echogenicity due UCA fragmentation. demonstrated that fragmentation was concomitant with inertial cavitation. The purpose this study evaluate relationship between stable thresholds UCAs as a function pulse duration. Determining would enable monitoring based...

Histotripsyutilizes focused ultrasound to generate bubble clouds for transcutaneous tissue liquefaction. Bubble activity maps are under development provide image guidance and monitor treatment progress. The aim of this paper was investigate the feasibility using plane wave B-mode passive cavitation images be used as binary classifiers histotripsy-induced Prostate phantoms were exposed histotripsy pulses over a range pulse durations (5-20 μs) peak negative pressures (12-23 MPa). Acoustic...

The hypothesis of this study was histotripsy, an ultrasound therapy that disrupts tissue mechanically through the action bubble clouds, increases short-term rate acute thrombus clearance for catheter-directed thrombolysis (CDT) in animal model. Thrombi formed femoral vein pigs were treated with CDT, or CDT and histotripsy (histotripsy+). Ultrasound (B-mode color Doppler) contrast fluoroscopy imaging data scored by four observers semi-quantitative evaluation each arm ordinal regression...

Passive cavitation imaging (PCI) derived metrics can serve as surrogates for the outcome of bubble-mediated therapies. is limited by poor axial resolution and side lobe artifacts, particularly when algorithms such delay, sum integrate (DSI) beamforming are used. Methods to improve PCI performance remain an active research area given need balance with computational complexity. The current study evaluated pth root compression (prDSI) using in vitro vivo data collected insonation parameters...

Histotripsy is a non-invasive focused ultrasound therapy that liquifies tissue via bubble activity. Conventional imaging used in current clinical practice to monitor histotripsy. Developing surrogate metrics for successful treatment outcomes remains an unmet need. The goal of this work was twofold. First, we investigated whether histotripsy clouds detected with nonlinear (chirp-coded subharmonic and without Volterra filtering) can be assess the ablation zone vitro. Second, evaluated...

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood, and high-risk disease resistant to intensive treatment. Histotripsy a focused ultrasound therapy under development for tissue ablation via bubble activity. The goal this study was assess outcomes histotripsy in xenograft model NB.Female NCr nude mice received NGP-luciferase cells intrarenally. Under image guidance, pulses were applied over distance 4-6 mm within tumors. Bioluminescence indicative viability...

The amplitude of the acoustic pressure required to nucleate a gas or vapor bubble in fluid, and have that undergo an inertial collapse, is termed cavitation threshold. magnitude threshold typically limited by mechanisms other than homogeneous nucleation such theoretical maximum never achieved. However, onset can be suppressed increasing static fluid. was measured ultrapure water at pressures up 30 MPa (300 bars) exciting radially symmetric standing wave field spherical resonator driven...

Although primarily known as an ablative modality, histotripsy can increase the efficacy of lytic therapy in a retracted venous clot model. Bubble cloud oscillations are primary mechanism action for histotripsy, and type bubble activity is dependent on pulse duration. A human model was perfused with without thrombolytic recombinant tissue plasminogen activator (rt-PA). The exposed to pulses single- or five-cycle duration peak negative pressures 0-30 MPa. within monitored via passive...

Histotripsy is a focused ultrasound therapy that ablates tissue through the mechanical action of cavitation. Histotripsy-initiated cavitation activity generated from shocked pulses scatter incidental nuclei (shock scattering histotripsy), or purely tensile (microtripsy). The Yang/Church model was numerically integrated to predict behavior exposed measured shock histotripsy pulses. bubble motion exhibited expansion only behavior, suggesting ablative pulse related maximum size bubble. analytic...

Echogenic liposomes loaded with the thrombolytic recombinant tissue-type plasminogen activator (rt-PA) are under development for treatment of ischemic stroke. These agents designed to co-encapsulate cavitation nuclei promote bubble activity in response ultrasound exposure, and enable localized delivery thrombolytic. Stable improves efficacy through enhanced fluid mixing. that encapsulate air-filled microbubbles nucleate scant stable 120 kHz intermittent have demonstrated equivalent rt-PA...

The prevalence of stroke worldwide and the paucity effective therapies have triggered interest in use transcranial ultrasound as an adjuvant to thrombolytic therapy. Previous studies shown that 120 kHz enhanced thrombolysis allowed efficient penetration through temporal bone. objective our study was develop accurate finite-difference model acoustic propagation skull based on computed tomography (CT) images. computational approach, which neglected shear waves, compared with a simple...

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective:</i> Histotripsy is a focused ultrasound therapy that ablates tissue via the action of bubble clouds. It under investigation to treat number ailments, including renal tumors. Ultrasound imaging used monitor histotripsy, though there remains lack definitive metrics confirm successful treatment outcomes. In this study, convolutional neural network (CNN) was developed segment ablation on...

Recent investigations of cavitation in fluids pressurized up to 30 MPa found that the intensity light emissions increased by 1000-fold over measured for single bubble sonoluminescence. A series measurements is reported here extend this original work resolving static pressure dependence shock wave and from first most energetic collapses, along with total energy event. Each these parameters was increase fluid. Furthermore, proportion stored acoustic system. These findings were corroborated...

Echogenic liposomes (ELIP), that can encapsulate both recombinant tissue-type plasminogen activator (rt-PA) and microbubbles, are under development to improve the treatment of thrombo-occlusive disease. However, enzymatic activity, thrombolytic efficacy, stable cavitation activity generated by this agent has yet be evaluated compared another established ultrasound-enhanced scheme. A spectrophotometric method was used compare rt-PA incorporated into ELIP (t-ELIP) rt-PA. An in vitro flow model...

Ultrasound contrast agents (UCAs) can be employed to nucleate cavitation achieve desired bioeffects, such as thrombolysis, in therapeutic ultrasound applications. Effective methods of enhancing thrombolysis with have been examined at low frequencies (&amp;lt;1 MHz) and amplitudes (&amp;lt;0.5 MPa). The objective this study was determine thresholds for two UCAs exposed 120-kHz ultrasound. A commercial agent (Definity®) echogenic liposomes were investigated the acoustic pressure threshold...

Histotripsy is a form of therapeutic ultrasound that liquefies tissue mechanically via acoustic cavitation. Bubble expansion paramount in the efficacy histotripsy therapy, and cavitation dynamics are strongly influenced by medium elasticity. In this study, an analytic model to predict histotripsy-induced bubble fluid was extended include effects Good agreement observed between predictions numerical computations utilizing highly nonlinear excitations (shock-scattering histotripsy) purely...