The right lung is slightly smaller than the left and its vessel count is markedly reduced, except for the apical segment of the right upper lobe. The right upper lobe artery is prominent, but the right basal artery can be traced into (really behind) the density of the right atrium. The silhouette of the heart and diaphragm margins is preserved. There is a clear linear density that crosses the right lower zone. It may represent a depressed horizontal fissure, but loss of right lower volume may result in a twisting of the greater fissure into the direction of the X-ray beam.

The bronchi of the right lung are outlined by contrast. There is some crowding of the lower lobe bronchi, which show some fusiform dilatation peripherally, particularly in middle lobe and medial and posterior basal segments of the right lower lobe. There is paring of the the distal branches of the abnormal bronchi.

Air-trapping in Bronchiolitis (case report)

Include consequences of childhood measles etc, Mcleod syndrome, failed secondary lung development in childhood.