title: Automated classification of lung bronchovascular anatomy in CT using AdaBoost.
abstract: Lung CAD systems require the ability to classify a variety of pulmonary structures as part of the diagnostic process. The purpose of this work was to develop a methodology for fully automated voxel-by-voxel classification of airways, fissures, nodules, and vessels from chest CT images using a single feature set and classification method. Twenty-nine thin section CT scans were obtained from the Lung Image Database Consortium (LIDC). Multiple radiologists labeled voxels corresponding to the following structures: airways (trachea to 6th generation), major and minor lobar fissures, nodules, and vessels (hilum to peripheral), and normal lung parenchyma. The labeled data was used in conjunction with a supervised machine learning approach (AdaBoost) to train a set of ensemble classifiers. Each ensemble classifier was trained to detect voxels part of a specific structure (either airway, fissure, nodule, vessel, or parenchyma). The feature set consisted of voxel attenuation and a small number of features based on the eigenvalues of the Hessian matrix (used to differentiate structures by shape). When each ensemble classifier was composed of 20 weak classifiers, the AUC values for the airway, fissure, nodule, vessel, and parenchyma classifiers were 0.984+/-0.011, 0.949+/-0.009, 0.945+/-0.018, 0.953+/-0.016, and 0.931+/-0.015, respectively. The strong results suggest that this could be an effective input to higher-level anatomical based segmentation models with the potential to improve CAD performance.
authors.affiliation: Department of Biomedical Physics, University of California Los Angeles, CA 90095, USA. rochs@mednet.ucla.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Ochs
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Goldin
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Abtin
authors.forename: Hyun J
authors.initials: HJ
authors.lastname: Kim
authors.forename: Kathleen
authors.initials: K
authors.lastname: Brown
authors.forename: Poonam
authors.initials: P
authors.lastname: Batra
authors.forename: Donald
authors.initials: D
authors.lastname: Roback
authors.forename: Michael F
authors.initials: MF
authors.lastname: McNitt-Gray
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Brown
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D006801:Humans; D008168:Lung / Q000033:anatomy & histology / Q000098:blood supply / Q000000981:diagnostic imaging*; D010363:Pattern Recognition, Automated / Q000379:methods*; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media