PhD Project – Optimized audio-visual fMRI for the guidance of brain stimulation

Neurological conditions are the number one cause of illness and disability worldwide. There are many treatments available involving stimulation of the brain - either by surgically implanting devices to control electrical signals in the brain, or by transmitting energy through the skull non-invasively. Every brain is structurally and functionally different. It can be difficult, if not impossible, to determine exactly which parts of the brain are involved in the control of different functions or processes, without some pre-treatment imaging or measurements. Functional MRI (fMRI) is one technique which can show doctors exactly which parts of the brain are involved in performing certain tasks, or processing certain types of information. During an fMRI scan, the person inside the scanner can be shown information or asked to perform certain tasks (such as making different movements, playing word games, or taking memory tests, for example). This technique is already used when planning for brain surgeries, so the surgeon can more effectively avoid damage to important parts of the brain while removing damaged or cancerous brain tissue. Most commonly, functional MRI tasks are shown to the person inside the scanner on a screen. This is because MRI scanners are so loud that it is incredibly challenging to convey information verbally. NordicNeuroLab, a world leader in the manufacture of equipment for the MR environment, is launching a new audio system for MRI. This overcomes the current challenges through the provision of high quality sound and active and passive noise cancellation. This opens up possibilities in audio based tasks for functional MRI. There is also potential to map specific areas of the brain using audio-visual tasks which have yet to be explored in detail. This project will work towards an optimized strategy for audio-visual fMRI for the guidance of brain stimulation treatments, and demonstrate the benefit of adding fMRI into current clinical workflows.

Brain stimulation techniques can be used to treat a variety of disorders related to movement, language or memory, but localization accuracy can be limited. Functional MRI (fMRI) is a method of brain mapping, giving maps of active brain regions in response to specific stimuli. Patients perform a specific task (paradigm) depending on the functional area of interest. The most common clinical application is in pre-surgical mapping for epilepsy or brain tumours, but research shows there is also potential for fMRI to find targets for therapeutic brain stimulation. fMRI paradigms are typically conveyed to the patient in the MRI scanner via a visual display. For patients who cannot take in the information visually, information may be conveyed audibly via headphones, but the noise of the MRI scanner poses a huge limitation in the ability to hear stimuli or instructions. NordicNeuroLab has produced a state-of-the-art noise cancelling audio system for use during MRI scanning. This opens up significant opportunities to improve the way stimuli are conveyed to fMRI patients, allowing better quality fMRI for a wider range of patients. We propose to develop and test functional MRI paradigms with the potential to instruct the best location for brain stimulation for the treatment of motor, language or memory related disorders. The student will: • Investigate differences and synergies in the use of visual versus auditory delivery of stimuli during fMRI for motor, language and memory tasks • Optimize scanning protocols and paradigms for motor, language and memory fMRI in healthy volunteers by investigating advanced MR acceleration techniques and adaptive paradigms, to allow as much sensitive and specific functional information as possible to be gathered during a single fMRI scan • Conduct a clinical study in patients undergoing brain stimulation, providing fMRI data to the neurosurgeon or in advance of surgery, and obtaining feedback on the usefulness of such data for guidance.