44 year old man with dyspnoea, cough and mild pyrexia.What pa of the lung is involved?

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.