title: Acetabular pneumatocyst containing air-fluid level.
abstract: The presence of intraosseous gas most commonly occurs in osteomyelitis, vacuum phenomenon, and postsurgery or posttraumatic states. Several cases of subchondral gas-filled lesions, called pneumatocysts, have also been described in the sacroiliac joint and clavicle, none of them with intralesional air-fluid level. These pneumatocysts are innocuous lesions of uncertain origin. We describe one case of acetabular pneumatocyst containing air-fluid level in a 62-year-old man with long-standing ankylosing spondylitis involving hip joint. To our knowledge, this is the first reported case of a pneumatocyst in an acetabular location containing air-fluid level.
authors.affiliation: Department of CT and MR Imaging, Institut de Diagnòstic per la Imatge, Hospital Duran i Reynals, Ciudad Sanitaria y Universitaria de Bellvitge, Autovía de Castelldefels km 2'7, E-08907 L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Narváez
authors.forename: J
authors.initials: J
authors.lastname: Narváez
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez-Mijarro
authors.forename: J C
authors.initials: JC
authors.lastname: Quintero
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000473:pathology; D001845:Bone Cysts / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005740:Gases; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013167:Spondylitis, Ankylosing / Q000150:complications; D014057:Tomography, X-Ray Computed
chemical_list: D005740:Gases