title: Morphology filter bank for extracting nodular and linear patterns in medical images.
abstract: OBJECTIVE
  Using image processing to extract nodular or linear shadows is a key technique of computer-aided diagnosis schemes. This study proposes a new method for extracting nodular and linear patterns of various sizes in medical images.
  
  
  METHODS
  We have developed a morphology filter bank that creates multiresolution representations of an image. Analysis bank of this filter bank produces nodular and linear patterns at each resolution level. Synthesis bank can then be used to perfectly reconstruct the original image from these decomposed patterns.
  
  
  RESULTS
  Our proposed method shows better performance based on a quantitative evaluation using a synthesized image compared with a conventional method based on a Hessian matrix, often used to enhance nodular and linear patterns. In addition, experiments show that our method can be applied to the followings: (1) microcalcifications of various sizes in mammograms can be extracted, (2) blood vessels of various sizes in retinal fundus images can be extracted, and (3) thoracic CT images can be reconstructed while removing normal vessels.
  
  
  CONCLUSIONS
  Our proposed method is useful for extracting nodular and linear shadows or removing normal structures in medical images.
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto-shi, Kumamoto, 860-8555, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Hashimoto
authors.affiliation: Department of Medical Physics, Faculty of Life Science, Kumamoto University, 4-24-1 Kuhonji, Kumamoto, Kumamoto, 862-0976, Japan. y_uchi@kumamoto-u.ac.jp.
authors.forename: Yoshikazu
authors.identifier: http://orcid.org/0000-0003-2083-4152
authors.initials: Y
authors.lastname: Uchiyama
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto-shi, Kumamoto, 860-8555, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Uchimura
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto-shi, Kumamoto, 860-8555, Japan.
authors.forename: Gou
authors.initials: G
authors.lastname: Koutaki
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto-shi, Kumamoto, 860-8555, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000465:Algorithms; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*
keywords: Computer-aided diagnosis; Filter bank; Mathematical morphology; Multiresolution representation