MR-guided focused ultrasound

Ultrasound has the ability to focus energy to a small point beyond the skull and is being widely explored by researchers as a tool for non-invasive neuromodulation. When combined with magnetic resonance imaging (MRI), focused ultrasound (FUS) can be precisely guided while the effects of FUS can be visualized at the network level using fMRI. We have developed systems to apply image-guided FUS neuromodulation in the MRI environment while imaging functional activity. These systems use optical tracking to guide FUS neuromodulation, and we have created transducer arrays for steerable FUS neuromodulation. The position of the probe can be detected using MR acoustic radiation force imaging, which is capable of detecting micron-scale displacements caused by the ultrasound beam in the brain. We have used these methods to modulate the somatosensory network in non-human primates, demonstrating that MRI-guided FUS is capable of exciting precise targets in somatosensory areas 3a/3b, causing downstream activations in off-target brain regions within the circuit which we simultaneously detected with fMRI.

Integrating ultrasound into MRI

Ultrasound-guided drug delivery

Microbubble contrast agents are micron sized lipid-encapsulated bubbles that oscillate in response to ultrasound. They are used clinically to enhance flow imaging, while research applications have explored how to use these oscillating bubbles to locally deliver drugs or genes for therapeutic purposes. We have developed methods to image microbubbles while simultaneously applying therapy. This powerful ability enables an all-in-one method to visualize and treat diseases. We are currently leveraging this technology in anti-cancer applications to map tumor vasculature while apply therapeutic ultrasound pulses to elicit an immune response. This work aims to expand the reach of immunotherapy to cancers that are not currently responsive.

Imaging and treating tumors with microbubbles

Featured Publications

Neuromodulation of sensory networks in monkey brain by focused ultrasound with MRI guidance and detection

Scientific Reports (2018)
Pai-Feng Yang, M. Anthony Phipps, Allen T. Newton, Vandiver Chaplin, John C. Gore, Charles F. Caskey & Li Min Chen
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Fast, Low-Frequency Plane-Wave Imaging for Ultrasound Contrast Imaging

Ultrasound in Medicine and Biology (2018)
Jiro Kusunose, Charles F. Caskey
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A random phased-array for MR-guided transcranial ultrasound neuromodulation in non-human primates

Physics in Medicine and Biology (2018)
Vandiver Chaplin, Marshal A Phipps, Charles F Caskey
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Dr. Charles Caskey

Principal Investigator


Jiro Kusunose

Staff Scientist


Tony (M. A.) Phipps

Graduate Student


Aparna Singh

Graduate Student


Tom Manuel

Graduate Student


Michelle Sigona

Graduate Student


Connor Krolak

Undergraduate Student


Jake Emrich

Undergraduate Student



We are currently seeking motivated imaging scientists at the graduate student and postdoctoral levels who wish to work at the intersection of MRgFUS, drug delivery, and neuroscience. Interested individuals can contact Charles Caskey.