title: Optical differentiation between malignant and benign lymphadenopathy by grey scale texture analysis of endobronchial ultrasound convex probe images.
abstract: BACKGROUND
  Morphologic and sonographic features of endobronchial ultrasound (EBUS) convex probe images are helpful in predicting metastatic lymph nodes. Grey scale texture analysis is a well-established methodology that has been applied to ultrasound images in other fields of medicine. The aim of this study was to determine if this methodology could differentiate between benign and malignant lymphadenopathy of EBUS images.
  
  
  METHODS
  Lymph nodes from digital images of EBUS procedures were manually mapped to obtain a region of interest and were analyzed in a prediction set. The regions of interest were analyzed for the following grey scale texture features in MATLAB (version 7.8.0.347 [R2009a]): mean pixel value, difference between maximal and minimal pixel value, SEM pixel value, entropy, correlation, energy, and homogeneity. Significant grey scale texture features were used to assess a validation set compared with fluoro-D-glucose (FDG)-PET-CT scan findings where available.
  
  
  RESULTS
  Fifty-two malignant nodes and 48 benign nodes were in the prediction set. Malignant nodes had a greater difference in the maximal and minimal pixel values, SEM pixel value, entropy, and correlation, and a lower energy (P < .0001 for all values). Fifty-one lymph nodes were in the validation set; 44 of 51 (86.3%) were classified correctly. Eighteen of these lymph nodes also had FDG-PET-CT scan assessment, which correctly classified 14 of 18 nodes (77.8%), compared with grey scale texture analysis, which correctly classified 16 of 18 nodes (88.9%).
  
  
  CONCLUSIONS
  Grey scale texture analysis of EBUS convex probe images can be used to differentiate malignant and benign lymphadenopathy. Preliminary results are comparable to FDG-PET-CT scan.
authors: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Herston, Australia; The University of Queensland, UQ Centre for Clinical Research, CSIRO Information and Communication Technologies Centre, The Royal Children's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia. Electronic address: phan.nguyen@internode.on.net.
authors: Phan
authors: P
authors: Nguyen
authors: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia.
authors: Farzad
authors: F
authors: Bashirzadeh
authors: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia.
authors: Justin
authors: J
authors: Hundloe
authors: The Australian eHealth Research Centre, CSIRO Information and Communication Technologies Centre, The Royal Children's Hospital, Herston, Australia.
authors: Olivier
authors: O
authors: Salvado
authors: The Australian eHealth Research Centre, CSIRO Information and Communication Technologies Centre, The Royal Children's Hospital, Herston, Australia.
authors: Nicholas
authors: N
authors: Dowson
authors: Queensland Children's Medical Research Institute, The Royal Children's Hospital, Herston, Australia.
authors: Robert
authors: R
authors: Ware
authors: Department of Respiratory Medicine, The Royal Children's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia.
authors: Ian Brent
authors: IB
authors: Masters
authors: Queensland PET Service, CSIRO Information and Communication Technologies Centre, The Royal Children's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia.
authors: Manoj
authors: M
authors: Bhatt
authors: Queensland PET Service, CSIRO Information and Communication Technologies Centre, The Royal Children's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia.
authors: Aravind Ravi
authors: AR
authors: Kumar
authors: Department of Thoracic Medicine, The Royal Brisbane and Women's Hospital, Herston, Australia; School of Medicine, Faculty of Health Sciences, University of Queensland, St. Lucia, QLD, Australia.
authors: David
authors: D
authors: Fielding
mesh_terms: D001980:Bronchi / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D019160:Endosonography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed