The frontal chest x-ray shows consolidation in the right middle lobe, silhouetting the right heart border.

The lateral chest x-ray shows the area of consolidation in the right middle lobe overlapping the heart, clearly bordered by the oblique fissure below and the horizontal fissure above. The horizontal fissure is slightly depressed indicating an element of collapse.

Interpretation: Right middle lobe collapse consolidation.

Reference: Fundamentals of Diagnostic Radiology by Brant and Helms, 4th Edition.