Effects of image reconstruction on fiber orientation mapping from multichannel diffusion MRI: reducing the noise floor using SENSE
Sotiropoulos, S.N.; Moeller, S.; Jbabdi, S.; Xu, J.; Andersson, J.L.; Auerbach, E.J.; Yacoub, E.; Feinberg, D.; Setsompop, K.; Wald, L.L.; Behrens, T.E.J.; Ugurbil, K.; Lenglet, C.
Purpose: To examine the effects of the reconstruction algorithm of magnitude images from multi-channel diffusion MRI on fibre orientation estimation.
Theory and Methods: It is well established that the method used to combine signals from different coil elements in multi-channel MRI can have an impact on the properties of the reconstructed magnitude image. Utilising a root-sum-of-squares (RSoS) approach results in a magnitude signal that follows an effective non-central-distribution. As a result, the noise floor, the minimum measurable in the absence of any true signal, is elevated. This is particularly relevant for diffusion-weighted MRI, where the signal attenuation is of interest.
Results: In this study, we illustrate problems that such image reconstruction characteristics may cause in the estimation of fibre orientations, both for model-based and model-free approaches, when modern 32-channel coils are employed. We further propose an alternative image reconstruction method that is based on sensitivity encoding (SENSE) and preserves the Rician nature of the single-channel, magnitude MR signal. We show that for the same k-space data, RSoS can cause excessive overfitting and reduced precision in orientation estimation compared to the SENSE-based approach.
Conclusion: These results highlight the importance of choosing the appropriate image reconstruction method for tractography studies that use multi-channel receiver coils for diffusion MRI acquisition.
|Journal Article Type||Article|
|Publication Date||Nov 18, 2013|
|Journal||Magnetic Resonance in Medicine|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Sotiropoulos, S., Moeller, S., Jbabdi, S., Xu, J., Andersson, J., Auerbach, E., …Lenglet, C. (2013). Effects of image reconstruction on fiber orientation mapping from multichannel diffusion MRI: reducing the noise floor using SENSE. Magnetic Resonance in Medicine, 70(6), doi:10.1002/mrm.24623|
|Keywords||Sum of Squares; SENSE; Rician; Non-central-X; Magnitude Image; Tractography|
|Copyright Statement||Copyright information regarding this work can be found at the following address: http://eprints.nottingh.../end_user_agreement.pdf|
|Additional Information||This is the peer reviewed version of the following article, which has been published in final form at https://onlinelibrary.w.../abs/10.1002/mrm.24623. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.|
Copyright information regarding this work can be found at the following address: http://eprints.nottingham.ac.uk/end_user_agreement.pdf