Quantitative Analysis in Functional Brain Imaging

Abstract

Molecular genetics and brain mapping have created two totally different revolutionary approaches in medicine and neuroscience. Microscopic and macroscopic approaches to understand brain function both in vitro and in vivo have provided an overwhelming amount of data concerning its operation in health and disease. Modern functional brain mapping techniques such as PET (positron emission tomography), SPE(C)T (single-photon emission computed tomography), fMRI (functional magnetic resonance imaging), EEG (electro-encephalography), MEG (magneto-encephalography), optical imaging and neuroanatomical tools have been used for assessing the functional organization of the human brain. Through these techniques, neuroscience has progressed greatly in the study of physiology, sensory and motor systems, vision, attention, memory, language and emotion in normal and pathological neurological or psychiatric conditions. The specific role of nuclear medical imaging techniques (PET and SPECT) in the expansion of our understanding of the pathophysiological mechanisms of neurological and psychiatric diseases and in the clinical management of patients is steadily progressing. PET and SPECT allow in vivo, noninvasive 3D imaging of regional cerebral blood flow, metabolism and neuroreceptor binding in the brain, amino acid synthesis or amyloid plaques. Since functional disturbances occur often earlier than structural once, a faster and more sensitive detection is possible. During recent years, non-invasive tomographic ‘molecular’ mapping of brain function with PET and SPECT has improved markedly through the development of dedicated instrumentation and the synthesis of new radiopharmaceuticals. Triple-headed gamma cameras with fanbeam collimation