Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model-driven reconstruction with phase-constrained highly-oversampled
  MRI   The Nyquist-Shannon theorem states that the information accessible by
discrete Fourier protocols saturates when the sampling rate reaches twice the
bandwidth of the detected continuous time signal. This maximum rate (the
NS-limit) plays a prominent role in Magnetic Resonance Imaging (MRI).
Nevertheless, reconstruction methods other than Fourier analysis can extract
useful information from data oversampled with respect to the NS-limit, given
that relevant prior knowledge is available. Here we present PhasE-Constrained
OverSampled MRI (PECOS), a method that exploits data oversampling in
combination with prior knowledge of the physical interactions between
electromagnetic fields and spins in MRI systems. In PECOS, highly
oversampled-in-time k-space data are fed into a phase-constrained variant of
Kaczmarz's algebraic reconstruction algorithm, where prior knowledge of the
expected spin contributions to the signal is codified into an encoding matrix.
PECOS can be used for scan acceleration in relevant scenarios by oversampling
along frequency-encoded directions, which is innocuous in MRI systems under
reasonable conditions. We find situations in which the reconstruction quality
can be higher than with NS-limited acquisitions and traditional Fourier
reconstruction. Besides, we compare the performance of a variety of encoding
pulse sequences as well as image reconstruction protocols, and find that
accelerated spiral trajectories in k-space combined with algebraic
reconstruction techniques are particularly advantageous. The proposed sampling
and reconstruction method is able to improve image quality for fully-sampled
k-space trajectories, while allowing accelerated or undersampled acquisitions
without regularization or signal extrapolation to unmeasured regions.

11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
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The categories of this paper are: econ