Master of Science Thesis Development of a phantom for optimisation and quality control in functional MRI (fMRI)

BOLD imaging is a useful and promising examination tool for mapping human brain functions, using the local alteration of blood oxygenation in the brain caused by neural activity. However, due to the weak signal response, optimisation of the entire methodology is important in BOLD imaging. To enable optimisation of various examination parameters, a fixed BOLD signal is often desirable. The phantom presented in this work is constructed of two agarose gel types with different T2 relaxation times, designed to simulate a BOLD response. The phantom has been tested in terms of reproducibility and stability, and additionally to optimise a signal parameter, in this work the echo time. The results show that the phantom can simulate a fixed-amplitude BOLD response used for optimisation of different parameters, such as the echo time. Additionally, the phantom is suitable for stability tests over longer times. Development of a phantom for optimisation and quality control in functional MRI (fMRI) Anders Nilsson 06-05-11 3