title: Images in thorax. The atoll sign.
authors.affiliation: Department of Radiology, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK. slfwalsh@gmail.com
authors.forename: Simon L F
authors.initials: SL
authors.lastname: Walsh
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Roberton
mesh_terms: D001706:Biopsy; D018549:Cryptogenic Organizing Pneumonia / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D014890:Granulomatosis with Polyangiitis / Q000175:diagnosis; D006801:Humans; D008168:Lung / Q000473:pathology; D008297:Male; D014057:Tomography, X-Ray Computed