HIGH FIELD MRI AND THE LABYRINTH: VESTIBULAR STIMULATION AND NEW IMAGING TECHNIQUES

ABSTRACT Dr. Bryan Ward is an assistant professor in the department of Otolaryngology-Head & Neck Surgery at the Johns Hopkins School of Medicine, where he is dedicating his clinical practice to vestibular disorders, otology and neurotology. He is seeking a mentored career development award in order to fill knowledge gaps in

imaging of the inner ear using MRI. His long-term goal is establishing an independent research program that is devoted to using imaging to improve the diagnosis and treatment of patients with dizziness and imbalance. The candidate proposes expanding on his prior work studying the physiologic effects of strong magnetic fields on

the inner ear vestibular system to imaging the fluid flow in the labyrinth of healthy chinchillas and humans. The training plan immerses Dr. Ward in the multidisciplinary research and clinical environments in the departments of radiology, neurology, biomedical engineering and otolaryngology at the Johns Hopkins University School of

Medicine. Specific training goals include: (1) receive training in the physics of MRI and how images are acquired, (2) complete training in MRI safety and performing prospective studies using imaging modalities, (3) pursue additional training in the ethical and responsible conduct of research, and (4) integrate his clinical

training in vestibular disorders with this knowledge as he develops into an independent investigator. High magnetic field MRIs can increase spatial and temporal resolution of images as a result of increased signal-to-noise ratio; however, these MRI machines also cause dizziness and vertigo in humans. We

previously showed that all healthy humans have nystagmus in an MRI and hypothesized that this is due to a Lorentz force occurring in the labyrinth. The specific aims of the proposed research are to: (1) test the hypothesis that a Lorentz force causes fluid flow that can be observed in vivo using phase contrast/flow

imaging in MRI, (2) to develop and implement a cost-effective countermeasure that minimizes the risk of vertigo in high-strength MRI fields, and (3) to image the human labyrinth in 7T and 3T MRI combining anatomic and flow imaging sequences. The study will involve chinchillas in aim 1 and the recruitment of healthy human

participants in aims 2 and 3. Completion of the proposed research plan will provide evidence for the cause of dizziness in strong MRI, a low-cost method to mitigate the effects of dizziness in an MRI regardless of the magnetic field strength, and support that improved MRI can provide higher resolution images of the labyrinth.

At the conclusion of this award, the candidate will be well-positioned to compete successfully for funding, having acquired relevant knowledge and skills to become a leader in using high-strength MRI to identify new vestibular pathophysiology and improve diagnosis of common conditions that cause dizziness and vertigo.