Which technique is able to detect in-vivo changes in the brain of a person developing Alzheimers disease?

Positron Emission Tomography (PET) is a technique that can detect in-vivo changes in the brain of a person developing Alzheimer's disease. It allows visualization of amyloid plaques and tau tangles, which are hallmark features of the disease. By using specific radiotracers, PET can identify these pathological changes before significant cognitive decline occurs, aiding in early diagnosis and monitoring of the disease's progression.