Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of breast-tissue x-ray attenuation by spectral mammography:
  solid lesions   Knowledge of x-ray attenuation is essential for developing and evaluating
x-ray imaging technologies. For instance, techniques to distinguish between
cysts and solid tumours at mammography screening would be highly desirable to
reduce recalls, but the development requires knowledge of the x-ray attenuation
for cysts and tumours. We have previously measured the attenuation of cyst
fluid using photon-counting spectral mammography. Data on x-ray attenuation for
solid breast lesions are available in the literature, but cover a relatively
wide range, likely caused by natural spread between samples, random measurement
errors, and different experimental conditions. In this study, we have adapted
the previously developed spectral method to measure the linear attenuation of
solid breast lesions. A total of 56 malignant and 5 benign lesions were
included in the study. The samples were placed in a holder that allowed for
thickness measurement. Spectral (energy-resolved) images of the samples were
acquired and the image signal was mapped to equivalent thicknesses of two known
reference materials, which can be used to derive the x-ray attenuation as a
function of energy. The spread in equivalent material thicknesses was
relatively large between samples, which is likely to be caused mainly by
natural variation and only to a minor extent by random measurement errors and
sample inhomogeneity. No significant difference in attenuation was found
between benign and malignant solid lesions, or between different types of
malignant lesions. The separation between cyst-fluid and tumour attenuation
was, however, significant, which suggests it may be possible to distinguish
cystic from solid breast lesions, and the results lay the groundwork for a
clinical trial. [cropped]

29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
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The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
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The categories of this paper are: adap-org