title: Enhancing automatic classification of hepatocellular carcinoma images through image masking, tissue changes and trabecular features.
abstract: BACKGROUND
  Recent breakthroughs in computer vision and digital microscopy have prompted the application of such technologies in cancer diagnosis, especially in histopathological image analysis. Earlier, an attempt to classify hepatocellular carcinoma images based on nuclear and structural features has been carried out on a set of surgical resected samples. Here, we proposed methods to enhance the process and improve the classification performance.
  
  
  METHODS
  First, we segmented the histological components of the liver tissues and generated several masked images. By utilizing the masked images, some set of new features were introduced, producing three sets of features consisting nuclei, trabecular and tissue changes features. Furthermore, we extended the classification process by using biopsy resected samples in addition to the surgical samples.
  
  
  RESULTS
  Experiments by using support vector machine (SVM) classifier with combinations of features and sample types showed that the proposed methods improve the classification rate in HCC detection for about 1-3%. Moreover, detection rate of low-grades cancer increased when the new features were appended in the classification process, although the rate was worsen in the case of undifferentiated tumors.
  
  
  CONCLUSIONS
  The masking process increased the reliability of extracted nuclei features. The additional of new features improved the system especially for early HCC detection. Likewise, the combination of surgical and biopsy samples as training data could also improve the classification rates. Therefore, the methods will extend the support for pathologists in the HCC diagnosis.
authors.affiliation: Department of Information Processing, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-S1-17 Nagatsuta, Midori, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Maulana Abdul
authors.initials: MA
authors.lastname: Aziz
authors.affiliation: Global Scientific Information and Computing Center, Tokyo Institute of Technology, 2-12-1-I7-6 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kanazawa
authors.affiliation: Global Scientific Information and Computing Center, Tokyo Institute of Technology, 2-12-1-I7-6 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Global Scientific Information and Computing Center, Tokyo Institute of Technology, 2-12-1-I7-6 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Fumikazu
authors.initials: F
authors.lastname: Kimura
authors.affiliation: Department of Information Processing, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-S1-17 Nagatsuta, Midori, Yokohama, Kanagawa 226-8503, Japan ; Global Scientific Information and Computing Center, Tokyo Institute of Technology, 2-12-1-I7-6 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamaguchi
authors.affiliation: Medical Solutions Division, NEC Corporation, 5-7-1 Shiba Minato-ku, Tokyo 108-8001, Japan.
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Kiyuna
authors.affiliation: Department of Information Processing, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-S1-17 Nagatsuta, Midori, Yokohama, Kanagawa 226-8503, Japan ; Medical Solutions Division, NEC Corporation, 5-7-1 Shiba Minato-ku, Tokyo 108-8001, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Medical Solutions Division, NEC Corporation, 5-7-1 Shiba Minato-ku, Tokyo 108-8001, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Saito
authors.affiliation: Faculty of Health and Medical Care, Saitama Medical University, 1397-1 Yamane, Hidaka-shi, Saitama 350-1241, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ishikawa
authors.affiliation: Faculty of Health and Medical Care, Saitama Medical University, 1397-1 Yamane, Hidaka-shi, Saitama 350-1241, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kobayashi
authors.affiliation: Department of Pathology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Tokiya
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Pathology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Hashiguchi
authors.affiliation: Department of Pathology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Michiie
authors.initials: M
authors.lastname: Sakamoto
keywords: Hepatocellular carcinoma; histopathological image classification; image masking; liver tissue; liver trabecular; support vector machine