Meeting Report: IEEE International Ultrasonics Symposium (IUS) 2021


The IEEE International Ultrasonics Symposium (IUS) 2021 was held as a virtual meeting September 11-16, 2021.

It featured a variety of two-day short courses and a week-long technical program with special sessions that included several presentations of interest to the focused ultrasound community.

“The invited speaker presentations showcased the wide breadth of focused ultrasound applications, including blood-brain barrier (BBB) opening, transcranial histotripsy, liquid biopsy, and neuromodulation,” said Matt Eames, PhD, the Foundation’s Director of Extramural Research and FUS Scholars programs. “It is great for the international attendees to see all the ways that focused ultrasound is making headway and becoming a disruptive technology.”

“The invited speakers for immunostimulation included focused ultrasound presentations on several ongoing studies,” said Frederic Padilla, PhD, the Foundation’s Research Director for Applied Physics. “I was also impressed with the innovations that are being made in developing endoscopic dual-mode transducers for prostate and histotripsy.”

Read below to learn about the focused ultrasound content at this meeting.


  • Invited speaker, Graeme Woodworth, MD, (University of Maryland, USA), presented “MRI-Guided, Acoustic Emissions-Informed, Microbubble-Enhanced Ultrasound for Controlled Blood-Brain Barrier Opening.” He described his study that provided proof of efficacy for BBB opening in a human clinical trial. The Maryland group is also working to correlate harmonic emissions and dosing for BBB opening.
  • Invited speaker, Zhen Xu, PhD, (University of Michigan, USA), presented “Histotripsy for Brain Applications.” She described how histotripsy can be used to treat a wide variety of locations and volumes without overheating the skull, even during hour-long treatments. The application also appears to have an excellent safety profile for transcranial use. It is guided by MRI or neuronavigation, and studies have been conducted in swine and murine (glioma) models. Histotripsy produced measurable immunomodulatory effects by reducing immune suppression cell populations and increasing pro-inflammatory molecules.
  • Invited speaker, Hong Chen, PhD, (Washington University in St. Louis, USA), presented “Sonobiopsy for Noninvasive and Spatiotemporally Controlled Brain Tumor Liquid Biopsies.” She described her studies using focused ultrasound to open the BBB and release tumor biomarkers (circulating tumor DNA) into the bloodstream. Her group is exploring the optimal parameters, types of biomarkers, and avenues to clinical translation.
  • Invited speaker, Hairong Zheng, PhD,  (Shenzhen Institute of Advanced Technology, China) , presented “Magnetic Resonance Imaging-Guided Ultrasound Brain Stimulation in Non-Human Primates.” Possible mechanisms for how focused ultrasound induces neuromodulation include alteration of mechanosensitive ion channels and kinetic stimulation of sodium or potassium channels in the cell membranes. His group used ultrasound neuromodulation to inhibit seizures in primates with epilepsy.


  • Invited speaker, Petros Mouratidis, PhD, (Institute of Cancer Research, United Kingdom), presented “The Combination of Focused Ultrasound and Immunotherapy for Pancreatic Cancer Therapy.” He described recent murine studies for pancreatic ductal adenocarcinoma that turned cold tumors hot using pulsed high-intensity focused ultrasound.
  • Invited speaker, Clifford Cho, MD, (University of Michigan Medical School, USA), presented “Immunotherapeutic Implications of Histotripsy Focused Ultrasound Ablation.” He described recent observations where histotripsy incited local pro-inflammatory immunogenic cell death and systemic anti-tumor immune responses.
  • Invited speaker, Richard Price, PhD, (University of Virginia, USA) presented “Promoting the Cancer Immunity Cycle with Focused Ultrasound.” He described recent studies using thermal and mechanical mechanism of focused ultrasound for breast cancer, melanoma, metastatic disease, and brain tumors.


  • Invited speaker, Constantin Coussios, PhD, (University of Oxford, UK) presented “Turn Up the Heat or Pop the Bubble? Clinical Translation of Ultrasound-Enhanced Drug Delivery for the Treatment of Solid Tumors.”
  • See abstract #5358 by Chulyong Kim (Georgia Tech, USA). This group concluded that hyperthermia had therapeutic potential for treating brain tumors and confirmed that it was effective for improving drug delivery.
  • See abstracts # 5249 and #5456 by Katherine Ferrara’s group (Stanford University, CA, USA). Mechanical and thermal focused ultrasound can both create an improved survival response, and the key to the adaptive immune response is adding an innate agonist. One study used tumor profiling to design the best focused ultrasound treatment.

Innovative Ultrasound Transducers

  • See abstract #4948 by Ivan Suarez-Castellanos et al. (LabTAU, France). This group is developing a miniature (endocavitary), dual-mode (imaging and therapy), high-frequency (2 to 4 MHz) device with high element density to allow dynamic focalization for the treatment of prostate cancer.
  • See abstract #5507 by Thomas Landry et al. (Virginia Tech, USA). This study co-registered imaging and histotripsy in rat brains using a combined endoscopic device. This group is also developing a 10-mm, 8-element endoscopic high-resolution transducer for imaging and histotripsy therapy (abstract #5362).

Comprehensive list* of abstract titles found by searching the Abstract Book for “focused ultrasound,” “HIFU,” and “histotripsy.”

  • 4020: Enhanced Histotripsy Using 256-Element Phased Array Combined with Multi-Focus Mode: A Preliminary Study by Mingzhu Lu, Ruixin Li, Jianyun Mao, Xuan Liu, Yi Zhang, Rongzheng Yang, Quan Zhang, Tingting Qi, and Mingxi Wan (Xi’an Jiaotong University, China)
  • 4056: Histotripsy Using B-Mode Real-Time Monitoring for the Treatment of In-Vivo Rabbit Kidney Tumors by Mingzhu Lu, Yehui Liu, Rongzheng Yang, Ruixin Li, Tingting Qi, Jianyun Mao, Quan Zhang, Xuan Liu, and Mingxi Wan (School of Life Science and Technology, China)
  • 4081: Noninvasive and Selective Activation of Neuronal Activity by Piezoelectric MoS2 Nanosheets with Focused Ultrasound by Ching-Hsiang Fan (National Cheng Kung University, Taiwan) and Chih-Kuang Yeh (National Tsing Hua University, Taiwan)
  • 4098: 3D High-Resolution and Fast Passive Ultrasound Imaging with Timing Synchronization and Low-Complexity Adaptive Beamforming for Cavitation Detection Under Short HIFU Pulses by Shukuan Lu, Yan Zhao, Lei Zhang, and Mingxi Wan (Xi’an Jiaotong University, China)
  • 4127: Heat Generation Induced by Cavitation Clouds with Ultrasound Contrast Agent in HIFU Field: A Phantom Study by Hua Cao, Yue Yuan, Jingke Zhang, Fu-Feng Lee, Jianwen Luo, and Yu An (Chongqing Medical University, China; and Tsinghua University, China)
  • 4193: Mutual Convolution of Dual Modes to Enhance Passive Acoustic Mapping for High Duty-Cycle HIFU Exposures Monitoring by Chunqi Li, Harry R. Clegg, Thomas M. Carpenter, Luzhen Nie, David M. J. Cowell, Steven Freear, and James R. McLaughlan (University of Leeds, United Kingdom)
  • 4358: Focused Ultrasound Assisted Gene and Sonodynamic Synergistic Therapy for Effectively Inhibiting Glioma by “All-in-One” Nanoplatform by yan Li, Mingting Zhu, Pengying Wu, Yujin Zong, Ayache Bouakaz, and Mingxi Wan (Université de Tours, France and Xi’an Jiaotong University, China)
  • 4450: Transient Flow Vector Distribution of Cavitation Bubbles in a Vessel Indued by Pulsed Focused Ultrasound Thrombolysis Based on Pyramid LK Optical Flow Method by Ting Ding, Huizhu Jia, Zhixin Tian, and Shuai Tian (North University of China, China)
  • 4465: Histotripsy Bubble Dynamics in a Collagenous Gel Phantom by Jacob Elliott, Andrea Arguelles, and Julianna Simon (Pennsylvania State University, USA)
  • 4479: Single-Sided Acoustic Levitation Based on Array of Focused Ultrasound Transducers by Longlong Wei, Guanjun Yin, and Jianzhong Guo (Shaanxi Normal University, China)
  • 4485: Transcranial Focused Ultrasound Stimulates Nucleus Tractus Solitarius to Regulate Blood Pressure by Fangyuan Cao, Dapeng Li, Chunhao Lai, Tianqi Xu, Mingxi Wan, and Siyuan Zhang (Xi’an Jiaotong University, China)
  • 4501: -6 dB Focus-Steering Region of a Fully-Electronically Planar HIFU Phased Array: A Preliminary Experimental Evaluation by Xiangda Wang, Jia Guo, Ping Li, Yan Yang, Shiguo Teng, Weijun Lin, and Jianlin Li (Institute of Acoustics, Chinese Academy of Sciences, China; Ruyuan Yao Autonomous Dongyangguang Industrial Development Co., Ltd, China; and YouJiang Medical University for Nationalities, China)
  • 4503: Modeling of Intensity-Modulated Focused Ultrasound in Pediatric Brain Tumors Using Acoustic Holograms by Sergio Jiménez-Gambín, Antonios Pouliopoulos, Zachary K. Englander, Noé Jiménez, Francisco Camarena, Elisa Konofagou, Stergios Zacharoulis, and Cheng-Chia Wu (Columbia University, USA; Columbia University Irving Medical Center, USA)
  • 4530: Novel Visualization Technique to Measure a Wide Range of Temperature Distribution Induced by High-Intensity Focused Ultrasound by Ryo Takagi, Kiyoshi Yoshinaka, Toshikatsu Washio, and Yoshihiko Koseki (National Institute of Advanced Industrial Science and Technology (AIST), Japan)
  • 4544: Skin Perforation Array Created by Focused Ultrasound for Effective Immunization Against Hepatitis B by Yang Mo, Jianpeng Wei, Siping Chen, Xin Chen, and Yaxin Hu (Shenzhen University, China)
  • 4549: Monitoring Stable Cavitation for Focused-Ultrasound BBB Disruption by Sonia Khan, Michael Smith, Laura Curiel, Ibrahim Youssef, Bhavya Shah, and Rajiv Chopra (University of Calgary, Canada; and UT Southwestern Medical Center, USA)
  • 4604: Liposomal Delivery to the Brain Using Rapid Short-Pulses of Focused Ultrasound by Sophie Morse, Aishwarya Mishra, Tiffany Chan, Rafael T. M. de Rosales, and James Choi (Imperial College London, United Kingdom; and King’s College London, United Kingdom)
  • 4624: Increase of the Treated Volume Using a Toroidal HIFU Transducer with a Minimal Number of Elements by Sophie Cambronero and David Melodelima (LabTAU, INSERM, Centre Léon Bérard, Université Lyon, France)
  • 4626: Fast, Large, and Noninvasive HIFU Treatment of the Liver Using a Toroidal Transducer. Preclinical Study in an In Vivo Porcine Model by Sophie Cambronero, Aurélien Dupre, Charles Mastier, and David Melodelima (LabTAU, INSERM, Centre Léon Bérard, Université Lyon, France)
  • 4627: Intra-Operative HIFU Treatment at the Hepato-Caval Confluence of the Liver. Preclinical Study in an In Vivo Porcine Model by Sophie Cambronero, Aurélien Dupre, Charles Mastier, Michel Rivoire, and David Melodelima (LabTAU, INSERM, Centre Léon Bérard, Université Lyon, France)
  • 4691: Towards Subject-Specific Therapy Planning for Non-Invasive Blood Brain Barrier Opening in Mice by Focused Ultrasound by Carl Gross, Torsten Hopp, Saskia Grudzenski-Theis, Stefan Heger, Marc Fatar, and Nicole Ruiter (Karlsruhe Institute of Technology, Germany; Mannheim University of Applied Sciences, Germany; and University of Heidelberg, Germany)
  • 4698: Real-Time Closed-Loop Feedback Control of Focused Ultrasound for Consistent Blood-Brain Barrier Opening by Chih-Yen Chien, Yan Gong, Yaoheng Yang, Yimei Yue, and Hong Chen (Washington University in St. Louis, USA)
  • 4754: Sonothermogenetics for Noninvasive and Cell-Type Specific Deep Brain Neuromodulation by Yaoheng Yang, Christopher Pacia, Dezhuang Ye, Lifei Zhu, Hongchae Baek, Yimei Yue, Jinyun Yuan, Mark Miller, Jianmin Cui, Joseph Culver, Michael Bruchas, and Hong Chen (University of Washington, USA; and Washington University in St. Louis, USA)
  • 4755: Static Magnetic Fields Dampen Focused Ultrasound-Induced Microbubble Cavitation and Attenuate Brain Drug Delivery Efficiency by Yaoheng Yang, Christopher Pacia, Dezhuang Ye, Yimei Yue, Chih-Yen Chien, amd Hong Chen (Washington University in St. Louis, USA)
  • 4765: Promoting the Cancer Immunity Cycle with Focused Ultrasound by Richard Price (University of Virginia, USA)
  • 4793: The Use of Focused Ultrasound in the Treatment of Pancreatic Ductal Adenocarcinoma by Petros Mouratidis and Gail Ter Haar (Institute of Cancer Research, United Kingdom)
  • 4828: The Dynamics of Histotripsy Bubble Clouds Nucleated from Echogenic Liposomes by Aarushi Bhargava, Samuel Hendley, Shaoling Huang, David McPherson, and Kenneth Bader (University of Chicago, USA; and University of Texas Health Science Center-Houston, USA)
  • 4948: Acoustic Characterization and In Vitro Evaluation of a Preclinical Dual-Mode CMUT Probe for Endocavitary Ultrasound-Guided HIFU Therapy by Ivan Suarez-Castellanos, Geoffroy de Sallmard, Alice Ganeau, Thomas Payen, Jean-Yves Chapelon, Nicolas Guillen, Nicolas Sénégond, and William Apoutou N’Djin (EDAP-TMS, France; LabTAU, INSERM, Centre Léon Bérard, Université Lyon, France; and VERMON, France)
  • 4953: Spatio-Temporal Analysis of Focused Ultrasound (FUS)-Evoked Local Field Potentials in an Ex Vivo Mouse Hippocampal Model by Ivan Suarez-Castellanos, Elena Dossi, Jérémy Vion-Bailly, Léa Salette, Jean-Yves Chapelon, Alexandre Carpentier, Gilles Huberfeld, and William Apoutou N’Djin (AP-HP, France; College de France, France; and INSERM, France)
  • 4962: Anti-Tumor Immune Implications of Histotripsy Focused Ultrasound Ablation by Clifford Cho (University of Michigan Medical School, USA)
  • 4968: Histotripsy Parameter Study on Murine Brain by Sang Won Choi, Sarah Duclos, Sandra Camelo-Piragua, Timothy Hall, Jonathan Sukovich, Aditya Pandey, and Zhen Xu (University of Michigan, USA)
  • 4978: Aberration Correction for Transcranial Histotripsy by Ning Lu, Timothy Hall, Jonathan Sukovich, and Zhen Xu (University of Michigan, USA)
  • 5009: Partial Histotripsy Ablation of Orthotopic Liver Tumor Generates Immune Response and Improves Survival in an In Vivo Metastatic Rodent Tumor Model by Tejaswi Worlikar, Man Zhang, Anutosh Ganguly, Timothy Hall, Lili Zhao, Jiaqi Shi, Fred Lee, Mishal Mendiratta-Lala, Clifford Cho, and Zhen Xu (University of Michigan, USA; University of Wisconsin, USA)
  • 5011: A 6,144-Element Fully Electronically Steerable MR-Guided Focused Ultrasound Phased Array by Ryan Jones, Yuexi Huang, Benjamin Lucht, Samuel Gunaseelan, Tyler Portelli, Pegah Aslani, Elizabeth David, and Kullervo Hynynen (Arrayus Technologies Inc., Canada; and Sunnybrook Research Institute, Canada)
  • 5012: High-Intensity Focused Ultrasound and Microbubble Induced Hyperthermia in Ex Vivo Porcine Liver by Eric Juang, Aswin Gnanaskandan, Chao-Tsung Hsiao, Lance De Koninck, and Michalakis Averkiou (Dynaflow Inc., USA; University of Washington, USA; and Worcester Polytechnic Institute, USA)
  • 5030: Acoustic Emission Based Closed-Loop Focused Ultrasound System for Targeted and Controlled BBB Opening in Rodents by Hohyun Lee, Yutong Guo, Scott Schoen Jr., Chulyong Kim, Levent Degertekin, and Costas Arvanitis (Georgia Institute of Technology, USA)
  • 5034: Transcranial Focused Ultrasound Neuromodulation on Visual Cortex with Optic Nerve Damage by Gengxi Lu, Xuejun Qian, Runze Li, Biju Thomas, Mark Humayun, and Qifa Zhou (University of Southern California, USA)
  • 5144: Mixed Focused Ultrasound (FUS)/Fluorescence Imaging Platform for Characterization of the Spatial-Temporal Dynamics of FUS-Evoked Calcium Fluxes in an In-Vitro Human Cell Model by Tom Aubier, Ivan Suarez Castellanos, Magali Perier, Alexandre Carpentier, and William Apoutou N’Djin (AP-HP, Pitié-Salpêtrière Hospital, France; LabTAU, INSERM, Centre Léon Bérard, Université Lyon, France)
  • 5168: HIFU Lesion Detection Based on Passive Elastography Using Conventional B-Mode Images: Application to Prostate Cancer by Thomas Payen, Sébastien Crouzet, Nicolas Guillen, Jean-Yves Chapelon, Cyril Lafon, and Stefan Catheline (EDAP-TMS, France; LabTAU, INSERM, Centre Léon Bérard, Université Lyon, France)
  • 5235: High Frequency Functional Ultrasound Imaging of Focused Ultrasound Nerve Stimulation by Stephen Lee, Hermes Kamimura, and Elisa Konofagou (Columbia University, USA)
  • 5236: Optically Tracked Steering and Correction of Transcranial Focused Ultrasound by Marshal Phipps, Thomas Manuel, Huiwen Luo, Pai-Feng Yang, Allen Newton, Li Min Chen, William Grissom, and Charles Caskey (Vanderbilt University, USA; and Vanderbilt University Medical Center, USA)
  • 5249: Immune Modulation of Thermal and Mechanical HIFU in a Murine Model of Breast Cancer by Brett Fite, James Wang, Aris Kare, Michael Chavez, Nisi Zhang, Elise Robinson, Azadeh Kheirolomoom, Matthew Silvestrini, Ryan Davis, Clifford Tepper, Alexander Borowsky, and Katherine Ferrara (Stanford University, USA; and University of California Davis, USA)
  • 5264: A 6.0 MHz Fresnel Lens Based Histotripsy Transducer by Jeffrey Woodacre, Matthew Mallay, and Jeremy Brown (Dalhousie University, Canada)
  • 5281: Focused-Ultrasound Blood-Brain Barrier Opening Induces Microglia Proliferation by Alina Kline-Schoder, Sana Chintamen, Rebecca Noel, Vilas Menon, Steve Kernie, and Elisa Konofagou (Columbia University, USA)
  • 5286: Tissue Temperature Effects on Cavitation During Focused Ultrasound by Erica McCune, Stephen Lee, and Elisa Konofagou (Columbia University, USA)
  • 5348: Microbubble Shell Properties and Ultrasound Excitation Frequency Can Modulate the Blood-Brain Barrier Phenotype by Yutong Guo, Hohyun Lee, and Costas Arvanitis (Georgia Institute of Technology, USA)
  • 5362: A 10 mm Aperture 8-Element Annular Histotripsy Array by Matthew Mallay, Jeffrey Woodacre, Thomas Landry, and Jeremy Brown (Dalhousie University, Canada)
  • 5451: Machine Learning Assisted Filtering of Harmonic Motion Imaging Guided High Intensity Focused Ultrasound Surgery (HMIgFUS) in an Ex Vivo Human Fibroadenoma Breast Tissue and In Vivo Breast Cancer Mouse by Xiaoyue Li, Stephen Lee, Murad Hossain, Niloufar Saharkhiz, Hermes Kamimura, Saurabh Singh, Indranil Basu, Chandan Guha, and Elisa Konofagou (Albert Einstein College of Medicine, USA; and Columbia University, USA)
  • 5456: HIFU and Agonist CD40 Enhance Immune Response in Breast and Pancreatic Cancer Models by James Wang, Brett Fite, Aris Kare, Bo Wu, Marina Rae, Spencer Tumbale, and Katherine Ferrara (Stanford University, USA)
  • 5477: Thermo-Mechanical Monitoring of Therapeutic Focused Ultrasound with Coaxial Ultrasound Imaging Configuration by Mengxuan Wang, Yijia Liu, Miaomiao Zhang, Qiong He, Nisi Zhang, Jianwen Luo, Zhifei Dai (Capital Normal University, China; Peking University, China; and Tsinghua University, China)
  • 5493: Transcranial Focused Ultrasound (tFUS) Pulsation Modulates Epileptic Neural Activity and Physiological Symptoms on a Pentylenetetrazol-Injected Rat Model In Vivo by Minseok Koo, Taewon Choi, and Jinhyoung Park (Sungkyunkwan University, Korea)
  • 5507: In-Vivo High-Resolution Imaging + Histotripsy in Rat Brains Using a Combined Endoscopic Device by Thomas Landry, Matthew Mallay, Nicholas Campbell, Eli Vlaisavljevich, and Jeremy Brown (Dalhousie University, Canada; and Virginia Polytechnic Institute and State University, USA)

*Many other abstracts apply to the field, although not specifically using “focused ultrasound” in the title. Search the Abstract Book for any other terms, applications, or authors of interest.