Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Towards non-parametric fiber-specific $T_1$ relaxometry in the human
  brain   Purpose: To estimate fiber-specific $T_1$ values, i.e. proxies for myelin
content, in heterogeneous brain tissue. Methods: A diffusion-$T_1$ correlation
experiment was carried out on an in vivo human brain using tensor-valued
diffusion encoding and multiple repetition times. The acquired data was
inverted using a Monte-Carlo inversion algorithm that retrieves non-parametric
distributions $\mathcal{P}(\mathbf{D},R_1)$ of diffusion tensors and
longitudinal relaxation rates $R_1 = 1/T_1$. Orientation distribution functions
(ODFs) of the highly anisotropic components of $\mathcal{P}(\mathbf{D},R_1)$
were defined to visualize orientation-specific diffusion-relaxation properties.
Finally, Monte-Carlo density-peak clustering (MC-DPC) was performed to quantify
fiber-specific features and investigate microstructural differences between
white-matter fiber bundles. Results: Parameter maps corresponding to
$\mathcal{P}(\mathbf{D},R_1)$'s statistical descriptors were obtained,
exhibiting the expected $R_1$ contrast between brain-tissue types. Our ODFs
recovered local orientations consistent with the known anatomy and indicated
possible differences in $T_1$ relaxation between major fiber bundles. These
differences, confirmed by MC-DPC, were in qualitative agreement with previous
model-based works but seem biased by the limitations of our current
experimental setup. Conclusions: Our Monte-Carlo framework enables the
non-parametric estimation of fiber-specific diffusion-$T_1$ features, thereby
showing potential for characterizing developmental or pathological changes in
$T_1$ within a given fiber bundle, and for investigating inter-bundle $T_1$
differences.

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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con