Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Post-processing techniques of 4D flow MRI: velocity and wall shear
  stress
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math