Abstract #1067

Koay C, Pierpaoli C, Chang L, Basser P

NICHD, National Institutes of Health

In general, only one estimate of a tensor is obtained in each voxel in a DTI experiment. Since the tensor estimate itself is derived from the noisy diffusion-weighted signals, here we derive the SD of the tensor and tensor-derived quantities by error propagation from the DW signals. The proposed technique is shown to produce precise estimate of the SD of FA. The simulation results show that the variability in tensor-derived quantities is largely due to the variability in the reference signal if the DTI model includes the reference signal as a parameter to be estimated. A simple procedure is provided to ameliorate this problem.