Time: October 22, 2025, Wednesday 1-2 PM US Eastern Time
Zoom Link:
Time: October 22, 2025, Wednesday 1-2 PM US Eastern Time
Zoom Link:
Seminar Title: Imaging and Sensing Methods for Guidance, Monitoring and Controlled Delivery of Transcranial Focused Ultrasound Therapies
Speaker: Dr. Emad S Ebbini, Professor, University of Minnesota Twin Cities
Abstract: Transcranial focused ultrasound (tFUS) is increasingly being used in a variety of clinical applications ranging from neuromodulation to targeted ablation. The advantages of tFUS are now well established, but its full potential is yet to be realized due to the challenges posed by the propagation through the skull. Beam distortions due to the skull result in significant levels of uncertainty in the focusing gain as well as potential shifting in the location of the focal spot. To mitigate these distortions, most of the existing clinical systems operate at conservatively low frequencies in the range of 250 – 700 kHz, where the effects of distortion and attenuation are acceptable. However, this compromises the specificity (localization) due to the relatively large size of the focal spot. Furthermore, it may limit the use of tFUS to targets in the central region of the brain away from the skull. Current clinical systems utilize MR imaging for guidance and monitoring of tFUS beams. While this is reasonable use of this image guidance modality in applications such as ablation and blood brain barrier opening, it may represent a significant burden in neuromodulation and similar applications. For the last decade, we have been developing imaging and sensing methods for guidance, monitoring and controlled delivery of tFUS using dual-mode ultrasound array (DMUA) technology. We have demonstrated the feasibility of imaging the tFUS-induced thermal and mechanical bioeffects in vivo at sub-therapeutic exposure levels using specialized DMUA imaging modes. More recently, we have demonstrated the feasibility of in situ exposimetry of tFUS application based on DMUA imaging and sensing of the tissue response at the target and in the path of the beam, including the skull. In this talk, we will describe the imaging and sensing capabilities of our DMUA systems and illustrate with examples from in vivo small animal and ex vivo transcranial delivery in cadaveric human head specimens. We will describe the synthetic aperture (SA) imaging mode (for guidance), and the single transmit focus (STF) imaging and sensing mode (for monitoring and close-loop control). We will also describe the in situ exposimetry approach based on DMUA imaging and compare it with the MR acoustic radiation force imaging (ARFI) approach currently being used for this purpose. We will conclude with an overview of a new generation of DMUA systems for tFUS applications, including wearable neuromodulation systems.
Seminar Title: Imaging and Sensing Methods for Guidance, Monitoring and Controlled Delivery of Transcranial Focused Ultrasound Therapies
Speaker: Dr. Emad S Ebbini, Professor, University of Minnesota Twin Cities
Abstract: Transcranial focused ultrasound (tFUS) is increasingly being used in a variety of clinical applications ranging from neuromodulation to targeted ablation. The advantages of tFUS are now well established, but its full potential is yet to be realized due to the challenges posed by the propagation through the skull. Beam distortions due to the skull result in significant levels of uncertainty in the focusing gain as well as potential shifting in the location of the focal spot. To mitigate these distortions, most of the existing clinical systems operate at conservatively low frequencies in the range of 250 – 700 kHz, where the effects of distortion and attenuation are acceptable. However, this compromises the specificity (localization) due to the relatively large size of the focal spot. Furthermore, it may limit the use of tFUS to targets in the central region of the brain away from the skull. Current clinical systems utilize MR imaging for guidance and monitoring of tFUS beams. While this is reasonable use of this image guidance modality in applications such as ablation and blood brain barrier opening, it may represent a significant burden in neuromodulation and similar applications. For the last decade, we have been developing imaging and sensing methods for guidance, monitoring and controlled delivery of tFUS using dual-mode ultrasound array (DMUA) technology. We have demonstrated the feasibility of imaging the tFUS-induced thermal and mechanical bioeffects in vivo at sub-therapeutic exposure levels using specialized DMUA imaging modes. More recently, we have demonstrated the feasibility of in situ exposimetry of tFUS application based on DMUA imaging and sensing of the tissue response at the target and in the path of the beam, including the skull. In this talk, we will describe the imaging and sensing capabilities of our DMUA systems and illustrate with examples from in vivo small animal and ex vivo transcranial delivery in cadaveric human head specimens. We will describe the synthetic aperture (SA) imaging mode (for guidance), and the single transmit focus (STF) imaging and sensing mode (for monitoring and close-loop control). We will also describe the in situ exposimetry approach based on DMUA imaging and compare it with the MR acoustic radiation force imaging (ARFI) approach currently being used for this purpose. We will conclude with an overview of a new generation of DMUA systems for tFUS applications, including wearable neuromodulation systems.