A5025057524- Ultrasound and Hyperthermia Applications
- Ultrasound Imaging and Elastography
- Photoacoustic and Ultrasonic Imaging
- Ultrasound and Cavitation Phenomena
- Advanced MRI Techniques and Applications
- Traumatic Brain Injury and Neurovascular Disturbances
- Ultrasound in Clinical Applications
- Cerebrospinal fluid and hydrocephalus
- Ultrasonics and Acoustic Wave Propagation
- Spinal Fractures and Fixation Techniques
- Nanoparticle-Based Drug Delivery
- Neonatal and fetal brain pathology
- Spinal Dysraphism and Malformations
- Cervical and Thoracic Myelopathy
- Spinal Cord Injury Research
- Advanced Radiotherapy Techniques
- Wireless Body Area Networks
- Nanoplatforms for cancer theranostics
- Medical Imaging Techniques and Applications
- Spine and Intervertebral Disc Pathology
- Tissue Engineering and Regenerative Medicine
- Alzheimer's disease research and treatments
- Mentoring and Academic Development
- Advanced Neuroimaging Techniques and Applications
- Brain Tumor Detection and Classification
Sunnybrook Hospital
2012-2025
Sunnybrook Research Institute
2016-2025
Sunnybrook Health Science Centre
2016-2025
Health Sciences Centre
2008-2024
University of Toronto
2012-2024
Canada Research Chairs
2020
To determine if focused ultrasound disruption of the blood-brain barrier (BBB) can be safely controlled by using real-time modulation treatment pressures on basis acoustic emissions from exposed microbubbles.All experiments were performed with approval institutional animal care committee. Transcranial (551.5 kHz, 10-msec bursts, 2-Hz pulse repetition frequency, 2 minute sonication) in conjunction circulating microbubbles was applied 86 locations 27 rats to disrupt BBB. Acoustic captured...
Noninvasive drug delivery to the brain remains a major challenge for treatment of neurological disorders. Transcranial focused ultrasound combined with lipid-coated gas microspheres injected into bloodstream has been shown increase permeability blood-brain barrier locally and transiently. Coupled magnetic resonance imaging, can be guided allow therapeutics administered in blood reach regions interest. Using this approach, we perform gene transfer from specific mouse brain. Focused was...
Microbubble-mediated disruption of the blood–brain barrier (BBB) for targeted drug delivery using focused ultrasound shows great potential as a therapy wide range brain disorders. This technique is currently at pre-clinical stage and important work being conducted in animal models. Measurements standing waves ex vivo rat skulls were an optical hydrophone geometry dependence was identified. Standing could not be eliminated through use swept frequencies, which have been suggested to eliminate...
There is an increasing interest in bubble-mediated focused ultrasound (FUS) interventions the brain. However, current technology lacks ability to spatially monitor interaction of microbubbles with applied acoustic field, something which critical for safe clinical translation these treatments. Passive mapping could offer a means monitoring microbubble emissions that relate bubble activity and associated bioeffects. In this study, hemispherical receiver array was integrated within existing...
Focused ultrasound (FUS)-mediated blood-brain barrier (BBB) opening recently entered clinical testing for targeted drug delivery to the brain. Sources of variability exist in current procedures, motivating development real-time monitoring and control techniques improve treatment safety efficacy. Here we used three-dimensional (3D) transcranial microbubble imaging calibrate FUS exposure levels volumetric BBB opening. Methods: Using a sparse hemispherical transmit/receive phased array, pulsed...
The feasibility of transcranial passive acoustic mapping with hemispherical sparse arrays (30 cm diameter, 16 to 1372 elements, 2.48 mm receiver diameter) using CT-based aberration corrections was investigated via numerical simulations. A multi-layered ray ultrasound propagation model based on CT-derived skull morphology developed. By incorporating skull-specific into a conventional beamforming algorithm (Norton and Won 2000 IEEE Trans. Geosci. Remote Sens. 38 1337–43), simulated source...
Microbubble-mediated focused ultrasound (US) opening of the blood-brain barrier (BBB) has shown promising results for treatment brain tumors and conditions such as Alzheimer disease. Practical clinical implementation US treatments would aim to treat a substantial portion brain; thus, safety large volumes must be investigated. This study investigated whether opened volume affects time BBB restored after treatment.Sprague Dawley rats (n = 5) received bilateral treatments. One hemisphere single...
Purpose: Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)‐based aberration corrections Jones et al. [Phys. Med. Biol. 58 , 4981–5005 (2013)]. Methods: A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen ex vivo skullcaps ( n = 4) emissions from narrow‐band fixed...
Focused ultrasound (FUS) phased arrays show promise for non-invasive brain therapy. However, the majority of them are limited to a single transmit/receive frequency and therefore lack versatility expose monitor treatment volume. Multi-frequency could offer variable transmit focal sizes under fixed aperture, detect different spectral content on receive imaging purposes. Here, three-frequency (306, 612, 1224 kHz) sparse hemispherical array (31.8 cm aperture; 128 transducer modules) was...
Rationale: Ultrasound-mediated opening of the Blood-Brain Barrier(BBB) has shown exciting potential for treatment Alzheimer's disease(AD).Studies in transgenic mouse models have that this approach can reduce plaque pathology and improve spatial memory.Before clinical translation occur safety method needs to be tested a larger brain allows lower frequencies used treat tissue volumes, simulating situations.Here we investigate BBB half large aged animal model with naturally occurring amyloid...
Ultrasound-activated nanobubbles are being widely investigated as contrast agents and therapeutic vehicles. Nanobubbles hold potential for accessing the tumor extravascular compartment, though this relies on clinically debated passive accumulation which evidence to date is indirect. We recently reported ultrasound-triggered conversion of high payload porphyrin-encapsulated microbubbles nanobubbles, with actively enhanced permeability local delivery. This platform holds implications...