Authors: Hu Chen,Yi Zhang,Yunjin Chen,Junfeng Zhang,Weihua Zhang,Huaiqiaing Sun,Yang Lv,Peixi Liao,Jiliu Zhou,Ge Wang
ArXiv: 1707.09636
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Abstract URL: http://arxiv.org/abs/1707.09636v3
Compressive sensing (CS) has proved effective for tomographic reconstruction
from sparsely collected data or under-sampled measurements, which are
practically important for few-view CT, tomosynthesis, interior tomography, and
so on. To perform sparse-data CT, the iterative reconstruction commonly use
regularizers in the CS framework. Currently, how to choose the parameters
adaptively for regularization is a major open problem. In this paper, inspired
by the idea of machine learning especially deep learning, we unfold a
state-of-the-art "fields of experts" based iterative reconstruction scheme up
to a number of iterations for data-driven training, construct a Learned
Experts' Assessment-based Reconstruction Network ("LEARN") for sparse-data CT,
and demonstrate the feasibility and merits of our LEARN network. The
experimental results with our proposed LEARN network produces a competitive
performance with the well-known Mayo Clinic Low-Dose Challenge Dataset relative
to several state-of-the-art methods, in terms of artifact reduction, feature
preservation, and computational speed. This is consistent to our insight that
because all the regularization terms and parameters used in the iterative
reconstruction are now learned from the training data, our LEARN network
utilizes application-oriented knowledge more effectively and recovers
underlying images more favorably than competing algorithms. Also, the number of
layers in the LEARN network is only 12, reducing the computational complexity
of typical iterative algorithms by orders of magnitude.