title: Significance of a visible major fissure on the frontal chest radiograph.
abstract: In this series of 80 patients, five factors are found to contribute to a visible major fissure. Volume changes in either the lower or upper lobes may cause fissural rotation from a coronal to a sagittal plane (26 patients). An incomplete or variant fissure with fluid abutting it (20 patients), or combinations of these factors (16 patients) will make the fissure visible. With either an incomplete fissure or a normal fissure in variant position, pleural thickening (seven patients) or adjacent consolidation (five patients) may make it possible to see the fissure. In normal patients, due to variation in fissural course, the fissure may be visible (six patients). In all of these situations, technical factors such as the divergent beam, position (lordotic), or projection (anteroposterior), may have contributory roles.
mesh_terms: D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D011187:Posture; D011446:Prospective Studies; D013902:Radiography, Thoracic