Metric Learning in Histopathological Image Classification: Opening the Black Box.

Journal: Sensors (Basel, Switzerland)
Published Date:

Abstract

The application of machine learning techniques to histopathology images enables advances in the field, providing valuable tools that can speed up and facilitate the diagnosis process. The classification of these images is a relevant aid for physicians who have to process a large number of images in long and repetitive tasks. This work proposes the adoption of metric learning that, beyond the task of classifying images, can provide additional information able to support the decision of the classification system. In particular, triplet networks have been employed to create a representation in the embedding space that gathers together images of the same class while tending to separate images with different labels. The obtained representation shows an evident separation of the classes with the possibility of evaluating the similarity and the dissimilarity among input images according to distance criteria. The model has been tested on the BreakHis dataset, a reference and largely used dataset that collects breast cancer images with eight pathology labels and four magnification levels. Our proposed classification model achieves relevant performance on the patient level, with the advantage of providing interpretable information for the obtained results, which represent a specific feature missed by the all the recent methodologies proposed for the same purpose.

Authors

  • Domenico Amato
    Dipartimento di Matematica e Informatica, Università degli studi di Palermo, Via Archirafi, 34, Palermo, 90123, Italy.
  • Salvatore Calderaro
    Department of Mathematics and Computer Science, University of Palermo, 90123 Palermo, Italy.
  • Giosuè Lo Bosco
    Dipartimento di Matematica e Informatica, Università degli studi di Palermo, Via Archirafi, 34, Palermo, 90123, Italy. giosue.lobosco@unipa.it.
  • Riccardo Rizzo
    National Research Council of Italy, ICAR-CNR, via Ugo La Malfa 153, Palermo, 90146, Italy.
  • Filippo Vella
    Institute for High-Performance Computing and Networking, National Research Council of Italy, 90146 Palermo, Italy.