On the Behavior of DTI and Q-Ball Derived Anisotropy Indices

Klaus H. Fritzsche¹, Bram Stieltjes², Frederik B. Laun³, Hans-Peter Meinzer¹

Anisotropy indices in diffusion imaging have never been systematically analyzed under conditions of heterogeneous fiber configurations. Furthermore, q-ball imaging indices have so far not been evaluated with respect to accuracy, precision, b-value dependency and contrast-to-noise ratio (CNR). This study performed a systematic analysis using Monte Carlo simulations and measurements in crossing fiber phantoms. The GFA (reconstructed with solid angle consideration) showed the lowest dependency on b-value and the best results regarding accuracy and precision. Its behavior in crossing fiber voxels was also preferable. Main drawback was its low CNR, especially in low anisotropy fibers.