[en] Molecular brain imaging has advanced significantly during the last few decades. Since the 1990s, positron emission tomography (PET) brain imaging with the radiopharmaceutical flurodeoxyglucose (FDG) and brain perfusion single photon emission computed tomography (SPECT) imaging have been critical tools for clinicians to diagnose various brain disorders such as Alzheimer’s disease and other forms of dementia. Even though neurodegenerative diseases cannot currently be cured, they often require different and specific approaches for symptomatic treatments, care planning and guidance for caregivers and family members. This means that more accurate differential diagnosis is essential for better patient care. More recently, amyloid PET imaging has become available in clinical settings in many countries. This technique detects one of the fundamental pathological processes that is associated with Alzheimer’s disease. It is specific to abnormal protein deposits in Alzheimer’s disease and provides a more detailed picture than the more general radiotracers used in the past. Its clinical value is currently being evaluated through multicentre trials. Other new PET imaging technologies, such as tau imaging and inflammation imaging, are being evaluated by the research community. All these efforts are not only aimed at helping day-to-day patient care, but also provide critical knowledge of the disease process itself that will help improve therapeutic developments.