<prompt> 44 year old man with dyspnoea, cough and mild pyrexia.What pa of the lung is involved?Right upper lobeRight middle lobeLeft middle lobeLeft lower lobe  <response>: The PA CXR shows increased airspace opacification in the right lower zone. The normal silhouette of the right hea border is obscured. On the lateral view the opacity is wedge-shaped and is located anteriorly. Diagnosis is Lobar pneumonia. Right middle lobe - the consolidation obscures the right hea border and on the lateral view it outlines the horizontal and oblique fissures . Note also that the horizontal fissure has been pulled inferiorly, indicating that there is a degree of collapse as well as consolidation. The patient should have a follow-up CXR after completing their antibiotic therapy to ensure complete resolution of the abnormality - occasionally there will be an underlying neoplasm. 