New Alzheimer's disease drugs have been developed in recent years. The key is to start treatment before dementia begins, in the stage of mild cognitive impairment, or MCI. But detecting MCI is time-consuming and difficult because there is no clear benchmark for diagnosing it. New devices have been developed for that purpose: a device to measure brain waves and a helmet-type PET scanner. We report on how this latest technology is helping with the battle against dementia.