Effects of Voxel Size, B-Factor and Averaging on the Test-Retest Reproducibility of DTI-Derived Fractional Anisotropy at 4T

Nico Dario Papinutto¹, Jorge Jovicich¹

Diffusion tensor imaging of in-vivo human brain provides insights into normal and abnormal white matter anatomical connectivity, but little is known about measurement reliability at very high magnetic field systems (> 3T). Here we assess the impact of acquisition variables (voxel size: 1.8^3 , 2.0^3 , and 2.5^3 mm^3 , b-value: 700, 1000, 1300 s/mm^2, number of acquisitions: 1, 2) on test-retest reproducibility of fractional anisotropy (FA) estimates in a group of healthy subjects at 4T. We found good consistency both in FA values and reproducibility reported from clinical scanners, even a the higher spatial resolution of (1.8 mm)^3.