An Evaluation of Contrast-To-Noise Ratios for Diffusion Anisotropy Metrics in the Presence of Multiple Fibres

Marta Morgado Correia¹, Virginia FJ Newcombe¹, Thomas Adrian Carpenter¹, Guy B. Williams¹

Despite the undeniable successes of FA (fractional anisotropy), DTI derived anisotropy metrics can be inaccurate in the presence of orientational heterogeneity. The present study compared the performance of alternative metrics of anisotropy, both using simulated and experimental data. Results show that most alternative metrics result in less significant drops of values between one and two-fibre populations. In addition, the use of a higher rank tensor results in increased ability to differentiate between tissue types, for both simulated and experimental data.