Research Project
6790006
DESCRIPTION (provided by applicant): Informatics tools are key to all stages of fMRI. However, there is very limited published information about several fundamental aspects of informatics tools. These issues include the knowledge of under what conditions operations performed by informatics tools are valid, comparisons of different tools to identify the conditions under which they are best utilized, and how to optimally process information when high-resolution phased array coils are utilized for faster and better acquisition of data. This project will address the three problems respectively. First, after conception and implementation of fMRI informatics tools, validation is an important step to ensure that the procedure fulfills all requirements set forth at the initial design stage. Qualitative analyses of various informatics tools have been done by using computer-simulated functional activation signals. However, these computer-simulated data are usually simply overlapped on top of anatomic images, they cannot reflect the real MR imaging process, such as the MR spin characteristics and noises introduced during the process, i.e., noise from MR power system, pre-amplifier, transmit/receive, and digitalization (A/D) error, etc. A remote-controlled "Smart Phantom" will be developed to produce simulated data but acquired from MRI system. These data will represent various BOLD models, contrast-to-noise ratio (CNR), signal intensities, and background physiological signals etc. Comparisons will be made with the widely used computer-simulated data. Validation of the Smart Phantom will be performed with both theoretical analysis and data of human subjects. All data associated with the use of the Phantom will be used to establish a benchmark database, an Informatics Development and Support Database for fMRI. Then, with availability of the Smart Phantom, characterization and comparison will be performed among the general-purpose statistical analysis packages. Sensitivity and specificity of functional activation detection will be investigated and compared by using the Receiver Operation Characteristics (ROC) curve under different levels of signal intensities, CNR, spatial resolution, and physiological spectral background. Pre-processing steps of fMRI analysis such as motion correction, spatial and temporal filtering will be characterized and compared. The third question is how to optimally use the information from phased array coils. The use of phased array coils has shown its advantages of faster acquisition, less motion artifact, and better sensitivity. How to optimally process the data from array coils to reconstruct high quality functional images is still a question, especially with the advent of SMASH/SENSE techniques. By using the Smart Phantom, various coils will be evaluated and compared. MRI reconstruction techniques will be compared to find an optimal way to acquire and process data. And last, validation and characterization will be performed using functional imaging data acquired from human subjects.
