We present a study of a potential technique to diagnose brain disease using quantum-entangled twin photons. Our method consists of preparing polarization-entangled photon pairs and sending one member of each pair through brain tissue that is either healthy or suffering brain disease, such as Alzheimers, glioblastoma or other. The tissue imparts a decohering effect on the state of the light that we examine via quantum state tomography. Our preliminary experimental data shows a difference in the entanglement measures between healthy tissue and tissue bearing Alzheimers disease. We also explore an imaging technique of brain tissue based on quantum entanglement.