title: Automatic detection of pleural effusion in chest radiographs.
abstract: Automated detection of Tuberculosis (TB) using chest radiographs (CXRs) is gaining popularity due to the lack of trained human readers in resource limited countries with a high TB burden. The majority of the computer-aided detection (CAD) systems for TB focus on detection of parenchymal abnormalities and ignore other important manifestations such as pleural effusion (PE). The costophrenic angle is a commonly used measure for detecting PE, but has limitations. In this work, an automatic method to detect PE in the left and right hemithoraces is proposed and evaluated on a database of 638 CXRs. We introduce a robust way to localize the costophrenic region using the chest wall contour as a landmark structure, in addition to the lung segmentation. Region descriptors are proposed based on intensity and morphology information in the region around the costophrenic recess. Random forest classifiers are trained to classify left and right hemithoraces. Performance of the PE detection system is evaluated in terms of recess localization accuracy and area under the receiver operating characteristic curve (AUC). The proposed method shows significant improvement in the AUC values as compared to systems which use lung segmentation and the costophrenic angle measurement alone.
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: pragnya.m@gmail.com.
authors.forename: Pragnya
authors.initials: P
authors.lastname: Maduskar
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: rick.philipsen@radboudumc.nl.
authors.forename: Rick H M M
authors.initials: RH
authors.lastname: Philipsen
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: jaime.melendezrodriguez@radboudumc.nl.
authors.forename: Jaime
authors.initials: J
authors.lastname: Melendez
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: ernst.scholten@radboudumc.nl.
authors.forename: Ernst
authors.initials: E
authors.lastname: Scholten
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: duncanchanda@gmail.com.
authors.forename: Duncan
authors.initials: D
authors.lastname: Chanda
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Helen@zambart.org.zm.
authors.forename: Helen
authors.initials: H
authors.lastname: Ayles
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: clara.sanchezgutierrez@radboudumc.nl.
authors.forename: Clara I
authors.initials: CI
authors.lastname: Sánchez
authors.affiliation: Radboud University Medical Center, Post 767, Radiology Department, PO box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: bram.vanginneken@radboudumc.nl.
authors.forename: Bram
authors.initials: B
authors.lastname: van Ginneken
mesh_terms: D000465:Algorithms; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D010363:Pattern Recognition, Automated / Q000379:methods*; D010996:Pleural Effusion / Q000000981:diagnostic imaging* / Q000209:etiology; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000150:complications / Q000000981:diagnostic imaging*
keywords: Automated; Computer-aided detection (CAD); Costophrenic angle; Pleural fluid; Tuberculosis