TY  - GEN
CY  - Cham, Switzerland
A1  - Lin, H
A1  - Zhou, Y
A1  - Slator, P
A1  - Alexander, D
T3  - Lecture Notes in Computer Science (LNCS)
KW  - Self supervision
KW  -  Mixture of experts
KW  -  Quantitative MRI
KW  -  Generalised super resolution
KW  -  Pseudo labels
N2  - Multi-modal and multi-contrast imaging datasets have diverse voxel-wise intensities. For example, quantitative MRI acquisition protocols are designed specifically to yield multiple images with widely-varying contrast that inform models relating MR signals to tissue characteristics. The large variance across images in such data prevents the use of standard normalisation techniques, making super resolution highly challenging. We propose a novel self-supervised mixture-of-experts (SS-MoE) paradigm for deep neural networks, and hence present a method enabling improved super resolution of data where image intensities are diverse and have large variance. Unlike the conventional MoE that automatically aggregates expert results for each input, we explicitly assign an input to the corresponding expert based on the predictive pseudo error labels in a self-supervised fashion. A new gater module is trained to discriminate the error levels of inputs estimated by Multiscale Quantile Segmentation. We show that our new paradigm reduces the error and improves the robustness when super resolving combined diffusion-relaxometry MRI data from the Super MUDI dataset. Our approach is suitable for a wide range of quantitative MRI techniques, and multi-contrast or multi-modal imaging techniques in general. It could be applied to super resolve images with inadequate resolution, or reduce the scanning time needed to acquire images of the required resolution. The source code and the trained models are available at https://github.com/hongxiangharry/SS-MoE.
ID  - discovery10135778
UR  - https://doi.org/10.1007/978-3-030-87231-1_5
PB  - Springer
N1  - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions.
TI  - Generalised Super Resolution for Quantitative MRI Using Self-supervised Mixture of Experts
AV  - public
SP  - 44
Y1  - 2021/09/21/
EP  - 54
ER  -