f-Sim: A quasi-realistic fMRI simulation toolbox using digital brain phantom and modeled noise

Functional Magnetic Resonance Imaging (fMRI) uses a noninvasive technique to study the functionality of the human brain by measuring the Blood Oxygenation Level Dependent (BOLD) signal and has been researched for decades. However, some potential problems still remain in achieving correct interpretation of BOLD-induced signals due to quite low signal levels, high noise levels, artifacts, lack of ground truth and a number of other inherent problems. We present here the development of a MATLAB based fMRI simulator (f-Sim) using digital phantom brain that generates quasi-realistic 4D fMRI volumes including modeled noise. Such 4D fMRI data can serve to hypothesize ground truth for experimentally acquired data under both task-evoked and resting state designs in investigation of localized or whole brain activation and functional connectivity patterns.