Abstract
The last 10 years have seen major changes in multicenter clinical trials involving diagnostic imaging in Alzheimer's disease (AD) and other dementias. The following broad trends can be clearly identified: changes from a) evaluation of a single modality to that of multiple modalities not restricted to images; b) diagnostic imaging to use as biomarkers; c) early diagnosis to very early diagnosis; and d) observational studies to interventional studies. Representative multicenter clinical trials related to dementia include "Japan Cooperative SPECT Study on Assessment of Mild Impairment of Cognitive Function" (J-COSMIC), "Study on Diagnosis of early Alzheimer's disease-Japan" (SEAD-Japan), and "Alzheimer's disease neuroimaging initiative" (ADNI). Aside from clinical evaluation and neuropsychological tests, evaluations in the J-COSMIC and SEAD-Japan studies were primarily based on cerebral blood flow SPECT and FDG-PET, respectively. Conversely, evaluation in the ADNI study, for the comprehensive diagnostic system, is based on imaging modalities such as MRI, FDG-PET, and amyloid PET, and various types of biomarkers such as genes and cerebrospinal fluid biomarkers. The standardized evaluation techniques regarding AD onset and progression established in these studies are expected to significantly contribute to the development of disease-modifying drugs.
