Alzheimer’s disease is a neurodegenerative disease, also known as dementia, and once the patient develops the disease, the condition progressively worsens, and in the middle and late stages of the disease, there will be obvious brain atrophy. However, medical imaging does not have clear features and cannot be used as the gold standard for diagnosis. CT examination can detect atrophy of brain cells and enlargement of the ventricular system. Magnetic resonance imaging (MRI) is much clearer, and in addition to brain atrophy and ventricular enlargement, it can also clearly show the specific areas of atrophy, such as bilateral temporal lobes or the hippocampus, and so on. CT perfusion imaging can be done in patients who have the condition, which can clearly observe the parietal lobe, temporal lobe, frontal lobe, and especially the hippocampal region in the medial temporal lobe bilaterally, which may have reduced blood flow and metabolism, and special imaging techniques may observe Aβ deposits in the brain.