Image based diagnostic aid system for interstitial lung diseases

  • Authors:
  • Azar Tolouee;Hamid Abrishami Moghaddam;Mohamad Forouzanfar;Masumeh Gity;Rahil Garnavi

  • Affiliations:
  • Department of Electrical Engineering, K.N. Toosi University of Technology, Tehran, Iran;Department of Electrical Engineering, K.N. Toosi University of Technology, Tehran, Iran and GRAMFC Unité de Génie Biophysique et Médical, Faculté de Médecine, Universit ...;School of Information Technology and Engineering, University of Ottawa, Ottawa, ON, Canada;Medical Imaging Center, Department of Radiology, Tehran University of Medical Sciences, Tehran, Iran;NICTA Victoria Research Laboratory, University of Melbourne, Melbourne, Australia

  • Venue:
  • Expert Systems with Applications: An International Journal
  • Year:
  • 2011

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Abstract

Automatic classification of lung tissue patterns in high-resolution computed tomography (HRCT) images of patients affected with interstitial lung diseases (ILD) is an important stage in the construction of a computer-aided diagnosis system. In this study, we propose a new image based system for classification of lung tissue patterns. The proposed system comprises three stages. In the first stage, the parenchyma region in HRCT lung images is separated using a set of thresholding, filtering and morphological operators. In the second stage, two sets of overcomplete wavelet filters, namely discrete wavelet frames and rotated wavelet frames, are utilized to extract features from defined regions of interest (ROIs) within parenchyma. Then, in the third stage, the fuzzy k-nearest neighbor algorithm is employed to perform the pattern classification. The proposed method is tested for classifying four different lung tissue patterns (ground glass, honeycombing, reticular, and normal) selected from a database of 339 images from 17 subjects. After applying our technique to classify these patterns in isolated ROIs, we extend the classification scheme to the whole lung in order to produce quantitative scores of abnormalities in lung parenchyma of patients. The performance of the proposed method is compared with two state-of-the-art texture based methods for lung tissue characterization and is also validated against experienced observers. The average kappa statistic of the agreement between two radiologists and the computer was found to be 0.6543 where as the average kappa statistic for the inter-observer agreement was 0.6848. We also performed an experiment to show the correlation between pulmonary function test parameters and quantitative scores of computerized system. Results show that extent of HRCT findings correlates significantly with functional impairment. The computer system is shown to approach the performance of the expert observers in diagnosing regions of interest and can help to produce objective measures of abnormal patterns in lung HRCT images.