Meeting Report: 183rd Meeting of Acoustical Society of America (ASA) 2022

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Key Points

  • The 183rd meeting of the Acoustical Society of America took place in Nashville, Tennessee, from December 5–9, 2022.
  • All abstracts are searchable on the meeting planning tool or in the PDF of the open access program.
  • The Foundation thanks Kevin J. Haworth, PhD, Schott Schoen, Jr., PhD, Adam Maxwell, PhD, and Eli Vlaisavljevich, PhD, for assistance in writing this meeting report.

The 183rd meeting of the Acoustical Society of America (ASA) took place in Nashville, Tennessee, from December 5–9, 2022. Dozens of abstracts were presented in the field of biomedical acoustics (BA) during the meeting, and joint sessions were held with the physical acoustics (PA), computational acoustics (CA), and signal processing acoustics (PA) technical committees. A broad range of topics were covered, and the material extended from fundamental science investigation to translational bench studies, preclinical studies, and in-human investigations in both imaging and therapeutic ultrasound.

The sessions relevant to focused ultrasound are listed below. All abstracts are available in a searchable PDF of the open access program or by using the searchable online meeting planning tool.

During the open BA Technical Committee meeting on Wednesday evening, several senior researchers, including Larry Crum, Christy Holland, and Mark Schafer, noted that the content of the meeting was excellent in its scope and depth. The range of invited speakers included great talks from both well-established members of the field and early-career speakers (such as Harriet Lea-Banks of Sunnybrook Research Institute and Dongwoon Hyun from Stanford). The early-career speakers introduced some fascinating new topic areas in ultrasound and provided a refreshing influx of new ideas and concepts. It was a reminder of how bright the future is for this research community and an inspiration for further research.

The following presentations were particularly notable:

  • 2aBAb6. “Volatile nanodroplets for neurological applications” (Lea-Banks, Sunnybrook Research Institute) discussed delivery of pentobarbital to specific regions of the brain without disruption of the blood-brain barrier and having specific anesthetic effects to those limited regions.
  • 2pBAb3. “Fibrin-targeted phase shift microbubbles outperform fibrin-targeted microbubbles for the treatment of microvascular obstruction” (Pacella, University of Pittsburgh) discussed results from a series of investigations into the use of nanodroplets plus ultrasound to increase perfusion after acute myocardial infarction. Bench, small animal, and large animal model studies were used with an excellent interplay in how each informed the observations of the others.
  • 3aBA1. “Acoustic droplet vaporization for nonthermal ablation of brain tumors” (Porter, University of Texas at Austin) discussed a series of studies performing mechanical ablation in the rat brain and the improved localization and more thorough treatment when nanodroplets were used as contrast nucleation agents.

A special session titled “Detection and quantification of bubble activity in therapeutic ultrasound” was held on Thursday. This session opened with Brian Fowlkes from the University of Michigan providing a summary of the outcomes of the Fall 2021 joint AIUM/FUSF workshop on this topic, as well as current efforts through IEC and other bodies to develop standards. This was followed by presentations in specific areas of cavitation detection and characterization by optical imaging, Doppler, MRI, and passive mapping.

A brief panel discussion then outlined considerations for standardizing measurements. Panelists generally agreed that measurements should be guided by application. When possible, it may be valuable to use relative measurements rather than absolute measurement values for the sake of simplicity. Panelists indicated that the technologies to perform at least relative measurements have been well-developed, but the processing and quantities derived from instruments that are specific to each application need further consensus.

An afternoon session further highlighted new research areas, including optical and acoustic characterization of histotripsy, tissue permeabilization, biofilm removal, drug delivery, and lithotripsy. New techniques for thermal characterization and computational modeling of microbubble clusters were also presented.

During Friday’s 5aBA session, there were several presentations that were relevant to the focused ultrasound community, including abstracts that directly considered focused ultrasound transducers and considerations for characterizing transducer with holography.

  • 5aBA2. “In vivo thermal ablation control using three-dimensional echo decorrelation imaging in swine liver” (Ghahramani, University of Cincinnati) examined the correlation between 3D acoustic correlation images and ablated regions in porcine liver toward controlled ablative treatment.
  • 5aBA3. “The impact of the central opening on nonlinear effects in ultrasound fields generated by Sonalleve V1 and V2 MR-HIFU systems” (V. Khokhlova, University of Washington and Moscow State University) compared the focal patterns and capabilities of the Sonalleve MR-HIFU V1 and V2 systems and described the HIFU-Beam simulation software, which allows time domain nonlinear simulation of annular arrays and layered media.
  • 5aBA4. “Palpating particles using the acoustic radiation force: A new approach to magnetic particle imaging” (Zarcone, Vanderbilt University) proposed using acoustic radiation force to induce motion for magnetic particle imaging.
  • 5aBA5. “Characterizing the steering performance of a diagnostic-therapeutic ultrasound array using measured and synthesized holograms” (Williams, University of Washington and Moscow State University) described the use of holography to characterize the surface of a linear ultrasound array with interleaving measurements to conserve time.
  • 5aBA6. “The use of acoustic holography for simultaneous characterization of various focus steering configurations in ultrasound fields generated by multi-element phased arrays” (V. Khokhlova, University of Washington) performed harmonic and time domain holograms for annular therapeutic focused ultrasound transducers.
  • 5aBA7. “A pipeline to enable large-scale generation of diverse 2D cardiac synthetic ultrasound recordings corresponding to healthy and heart failure virtual patients” (Burman, Katholieke Universiteit Leuven) described the use of augmentation tools for the generation of realistic myocardial velocity profiles toward the generation of large ultrasound training sets for machine learning.
  • 5aBA8. “Contrast-enhanced ultrasound to detect active bleeding” (Schoen, Jr., Harvard Medical School and Massachusetts General Hospital) described methods and in vitro models used to establish the feasibility of microbubbles to assist with the detection of hemorrhage.
  • 5aBA9. “Effect of acoustic output on fetal ultrasound color Doppler performance” (Huber, Duke University) described the setting of as low as reasonably achievable (ALRA) for Doppler ultrasound in neonatal imaging.
  • 5aBA10. “Exploring the benefits of spatial and temporal block-wise filtering architectures” (Weeks, Vanderbilt University) which evaluated the use of spatial and temporal block-wise filtering of a high frame rate liver imaging stack.

Additional focused ultrasound–related abstracts are list below:

  • 2pBAa7: Deep-learning based insitu ultrasound thermometry for thermal ablation monitoring (Anand, University of Rochester)
  • 2pBAb4. Low cost and low energy 3D volumetric histotripsy using nanodroplet vaporization (Glickstein, Tel Aviv University)
  • 2pBAb5. Nanoparticle-mediated histotripsy using dual-frequency histotripsy pulsing: Comparison of bubble-cloud characteristics and ablation efficiency (Edsall, Virginia Tech)
  • 3aBA3. Neuronavigation-guided transcranial histotripsy, results in a cadaveric model (Sukovich, University of Michigan)
  • 3aBA4. Transcranial focused ultrasound as a treatment for hypertension (Lea-Banks, Sunnybrook Research Institute)
  • 3aBA6. Image guidance and beam localization for transcranial focused ultrasound therapy (Phipps, Vanderbilt University Medical Center)
  • 3aBA7. Generating patient-specific acoustic simulations for transcranial focused ultrasound procedures based on optical tracking information (Sigona, Vanderbilt University)
  • 3aBA8. Synergistic effects of microbubble-mediated focused ultrasound and radiotherapy in a F98 glioma model (Fletcher, Brigham and Women’s Hospital/Harvard Medical School)
  • 4aBAa3. Passive and active Doppler methods and metrics to quantify inertial cavitation induced by pulsed focused ultrasound (T. Khokhlova, University of Washington)
  • 4aPAa4. Optically excited nanoparticle enhanced high intensity focused ultrasound therapy of in vivo cancer models (McLaughlan, University of Leeds)
  • 4aPAa6: Detection of HIFU lesions by optical coherence tomography (Everbach, Swarthmore College)
  • 4pCA3. Viscoelastic transcranial wave propagation modeling for nNeuronavigated focused ultrasound procedures in humans (Pichardo, University of Calgary)
  • 4pBAa5. 3D-printed gradient-index phononic crystal lens for transcranial focused ultrasound (Kohtanen, Georgia Institute of Technology)
  • 4pBAb1. Thrombolytic efficacy of histotripsy combined with thrombolytic-loaded echogenic liposomes (Centner, University of Chicago)
  • 4pBAb3. Effects of pulse repetition frequency on bubble cloud characteristics and ablation for single-cycle histotripsy (Simon, Virginia Tech)
  • 4pBAb5. Characterization and monitoring of cavitation behavior induced by a dual-mode pulsed high-intensity focused ultrasound array (Williams, University of Washington)
  • 4pBAb6. Extension of boiling histotripsy lesions by axial focus steering during pulse delivery (Thomas, University of Washington)
  • 4pBAb7. Histotripsy significantly decreases tumor viability in neuroblastoma xenograft model (Iwanicki, University of Chicago)
  • 4pBAb5. Characterization and monitoring of cavitation behavior induced by a dual-mode pulsed high-intensity focused ultrasound array (Williams, University of Washington)
  • 4pBAb8. Extending the iterative nonlinear contrast source method to simulate mutual interaction in large populations of microbubbles (Verweij, Delft University of Technology)
  • 4pBAb9. Simulating multiple scattering inside a population of nonlinearly oscillating microbubbles using the iterative nonlinear contrast source method (Matalliotakis, Delft University of Technology)
  • 4pBAb11. Bubble-cloud characteristics and ablation Efficiency in dual-frequency intrinsic threshold histotripsy (Edsall, Virginia Tech)
  • 4pBAb13. Passive and Doppler-based assessment of cavitation activity induced by pulsed focused ultrasound (Song, University of Washington)
  • 5aBA2. In vivo thermal ablation control using three-dimensional echo decorrelation imaging in swine liver (Ghahramani, University of Cincinnati)

The Foundation thanks Kevin J. Haworth, PhD, FAIUM, associate professor and director of data and analytics for the medical sciences baccalaureate program, University of Cincinnati; Scott J. Schoen, Jr., PhD, a postdoctoral fellow in the Department of Radiology at Harvard Medical School and Massachusetts General Hospital; Adam Maxwell, PhD, research associate professor in the Department of Urology at the University of Washington; and Eli Vlaisavljevich, PhD, associate professor in the Department of Engineering and Mechanics at the Virginia Tech – Wake Forest School of Biomedical Engineering and Sciences, for assistance in writing this meeting report.