Authors:
D. G, J. Haueisen, J. R. Reichenbach; Jena/DE
DOI:
10.1594/ECR03/C-0944
Conclusion
The first experiment shows that the influences of inaccurately determined b-values are not negligible in diffusion weighted imaging. The contribution of imaging gradient pulses and corresponding cross-terms on the b-values is more prominent with weak diffusion gradients. However, determining the full diffusion tensor by taking into account all sequence gradient pulses is necessary in case of anisotropic media, such as the human brain.The results of the second part demonstrate that it is possible to determine the quality of an application scheme by calculating the factor kappa. Applying the optimized gradient scheme which corresponds to the minimum value of kappa, the variance of the DW images is distributed among the variances of the single tensor elements in such a way, that the sum of the variances of these elements is minimized.In either case the findings of both investigations should help to improve the quality of diffusion tensor imaging. Determining accurate b-values eliminates a systematic error and using an optimal tensor scheme increases the accuracy of the calculated tensor elements.