@article{ddd.uab.cat:283594,
      author = {Ungan, Gulnur Semahat and Arús i Caraltó, Carles and Vellido,
               Alfredo and Julià Sapé, Ma. Margarita},
       title = {A comparison of non-negative matrix underapproximation methods
               for the decomposition of magnetic resonance spectroscopy data
               from human brain tumors},
     journal = {NMR in Biomedicine},
        year = {2023},
       pages = {#e5020--},
       month = {7},
        note = {Altres ajuts: acords transformatius de la UAB},
    abstract = {Magnetic resonance spectroscopy (MRS) is an MR technique that
               provides information about the biochemistry of tissues in a
               noninvasive way. MRS has been widely used for the study of brain
               tumors, both preoperatively and during follow-up. In this study,
               we investigated the performance of a range of variants of
               unsupervised matrix factorization methods of the non-negative
               matrix underapproximation (NMU) family, namely, sparse NMU,
               global NMU, and recursive NMU, and compared them with convex non-
               negative matrix factorization (C-NMF), which has previously shown
               a good performance on brain tumor diagnostic support problems
               using MRS data. The purpose of the investigation was 2-fold:
               first, to ascertain the differences among the sources extracted
               by these methods; and second, to compare the influence of each
               method in the diagnostic accuracy of the classification of brain
               tumors, using them as feature extractors. We discovered that,
               first, NMU variants found meaningful sources in terms of
               biological interpretability, but representing parts of the
               spectrum, in contrast to C-NMF; and second, that NMU methods
               achieved better classification accuracy than C-NMF for the
               classification tasks when one class was not meningioma.},
         doi = {10.1002/nbm.5020},
         url = {https://ddd.uab.cat/record/283594},
}