title: Grey scale texture analysis of endobronchial ultrasound mini probe images for prediction of benign or malignant aetiology.
abstract: OBJECTIVE
  Expert analysis of endobronchial ultrasound mini probe (EBUS-MP) images has established subjective criteria for discriminating benign and malignant disease. Minimal data are available for objective analysis of these images. The aim of this study was to determine if greyscale texture analysis could differentiate between benign and malignant lung lesions.
  
  
  METHODS
  Digital EBUS-MP images with a gain setting of 10/19 and contrast setting of 4/8 from 2007 until 2012 inclusive were included. These images had an expert-defined region of interest (ROI) mapped. ROI were analysed for the following greyscale texture features: mean pixel value, difference between maximum and minimum pixel value, standard deviation of the mean pixel value, entropy, correlation, energy and homogeneity. Significant greyscale texture features differentiating benign from malignant disease were used by two physicians to assess a validation set.
  
  
  RESULTS
  A total of 167 images were available. The first 85 lesions were used in the prediction set. Benign lesions had larger differences between maximum and minimum pixel values, larger standard deviations of the mean pixel values and higher entropy than malignant lesions (P < 0.0001 for all values). A total of 82 peripheral lesions were in the validation set. Physician 1 correctly classified 63/82 (76.8%) with a negative predictive value (NPV) for malignancy of 82% and positive predictive value (PPV) of 75%. Physician 2 correctly classified 62/82 (75.6%) with a NPV of 100% and PPV of 71.0%.
  
  
  CONCLUSIONS
  Greyscale texture analysis of EBUS-MP images can help establish aetiology with a high NPV for malignancy.
authors.affiliation: Department of Thoracic Medicine, The Royal Adelaide Hospital, Adelaide, South Australia.
authors.forename: Phan
authors.initials: P
authors.lastname: Nguyen
authors.affiliation: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
authors.forename: Farzad
authors.initials: F
authors.lastname: Bashirzadeh
authors.affiliation: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
authors.forename: Justin
authors.initials: J
authors.lastname: Hundloe
authors.affiliation: The Australian eHealth Research Centre, CSIRO Information and Communication Technologies Centre, Brisbane, Queensland, Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Salvado
authors.affiliation: The Australian eHealth Research Centre, CSIRO Information and Communication Technologies Centre, Brisbane, Queensland, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Dowson
authors.affiliation: Queensland Children's Medical Research Institute, Brisbane, Queensland, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Ware
authors.affiliation: Department of Respiratory Medicine, The Royal Children's Hospital, Brisbane, Queensland, Australia.
authors.forename: Ian Brent
authors.initials: IB
authors.lastname: Masters
authors.affiliation: Queensland PET Service, The Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
authors.forename: Aravind
authors.initials: A
authors.lastname: Ravi Kumar
authors.affiliation: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Fielding
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D001980:Bronchi / Q000000981:diagnostic imaging; D019160:Endosonography / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D064847:Multimodal Imaging; D012372:ROC Curve
keywords: bronchoscopy and interventional technique; endobronchial ultrasound; image analysis; lung cancer