Dielectric Measurements of Brain Tissues with Alzheimer’s Disease Pathology in the Microwave Region

Relative permittivity and conductivity of brain tissue samples with severe form of Alzheimer’s disease was measured and compared to those of healthy brain tissues. The brain tissue samples contained a substantial amount of beta-amyloid plaques and tau tangles, both of which are key indicators of Alzheimer’s disease in a patient. The experiments were performed at frequencies from 20 MHz to 3 GHz when samples were defrosted at 5°C using a vector network analyzer and dielectric probes. A software was used to capture the dielectric properties and analyzed further. Two main categories of tissue samples were considered: the grey matter and white matter of the brain. Both of these categories were from the frontal cortex of the brain. In both categories, certain distinctions have been found in the measured dielectric properties that differ from healthy human brain tissues. The results from this novel study indicates a key characteristic that can be exploited in detecting plaques and tangles in the brain. In addition, this result indicates that radio frequency imaging techniques can potentially be used as a diagnostic method for detecting and monitoring Alzheimer’s disease.