Apparent diffusion coefficient dependent fMRI: Spatiotemporal characteristics and implications on calibrated fMRI

In this manuscript, we review the development of an alternative functional magnetic resonance imaging (fMRI) contrast mechanism based on the apparent diffusion coefficient (ADC), in light of the recent progress in other complementary functional imaging contrasts sensitive to cerebral blood flow (CBF) and cerebral blood volume (CBV). Specifically, we discuss the spatial and temporal characteristics of ADC fMRI in localizing neuronal activities, and also draw inference on its potential applicability to achieve fast calibrated fMRI. We found that optimized dynamic ADC contrast can lead to improved spatial localization in small vessel networks close to the true neuronal activities, while having the potential to simultaneously generate the blood oxygenation level‐dependent (BOLD) and CBF/CBV contrasts required in a calibrated fMRI experiment. With sufficient signal‐to‐noise ratio (SNR) and temporal resolution, fMRI based on thedynamic ADC contrast may prove to be an efficient technique toachieve accurate and quantitative measures of neuronal activities. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 42–50, 2010