FINDINGS:

These two frontal films, made nine years apart, show progressive enlargement of the main and right pulmonary arteries.
The main pulmonary artery is visible on the left side of the mediastinum, between the aorta and the left heart border. The right PA is the right hilum. The left PA is also enlarged, but is hidden by the main PA.

PATTERN:

These changes are clearly abnormalities of the vessels and the pattern is thus Vascular.

DIFFERENTIAL DIAGNOSIS:

Enlarged pulmonary arteries are usually the result of excessive pressure backing up from the arterioles and capillaries.
The most common causes are diffuse lung disease, most often COPD, and chronic thromboembolic disease. Less common are ideopathic pulmonary hypertension and left to right cardiac shunts.

DIAGNOSIS:

Pulmonary Hypertension secondary to ASD