Emerging approaches to image the structure and function of the human brain would drastically benefit from exquisitely sensitive yet robust and easy-to-use magnetic field sensors.
Magnetoencephalography (MEG) is about non-invasively measuring electric brain activity through the neurally-generated magnetic fields. While the SQUID-sensor-based MEG is already an established technique, overcoming its current performance and commercial limits calls for a breakthrough in sensor technology; the sensors should be more sensitive, they should be brought closer to the scalp to increase spatial resolution, the sensor array should be malleable to the head size and shape of the subject or patient, and the sensors should operate without cryogenics for low running costs and simple construction. With such improvements, MEG could be a future replacement of the invasive, surgically-implanted recording electrodes currently applied in patients suffering from epilepsy to localize the epileptogenic area.
Ultra-low-field magnetic resonance imaging (ULF–MRI) is a safe, potentially low-cost future imaging technology, which has uniquely high contrast e.g. for certain tumor types. In ULF–MRI, the low-frequency (< 20 kHz) NMR signals are detected magnetically, without using tuned RF coils as in conventional high-field MRI. Like MEG, ULF–MRI would greatly benefit from advancements in magnetic sensor technology; the performance of the current ULF–MRI systems is limited largely by the sensitivity of the sensors. Compared to the state of the art, an order-of-magnitude reduction in the sensor noise level (down to sub-fT level) would greatly improve image quality and shorten the measurement time, thus helping ULF–MRI to become a clinically viable technology.
In this talk, I will briefly describe the current state of MEG and ULF-MRI as medical imaging modalities and illustrate how improvements in magnetic sensing technology could boost their performance as diagnostic tools and increase their commercial potential.