Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Massive enlargement of the pulmonary arteries is again noted consistent with known pulmonary arterial hypertension . This is accentuated by low lung volumes and bronchovascular crowding . No definite consolidation or edema is noted . The cardiac silhouette is stable in size . No effusion or pneumothorax is noted . The osseous structures are grossly unremarkable . There is linear atelectasis in the left perihilar region .
    OUTPUT:
    
Findings consistent with known pulmonary hypertension . No acute pulmonary process identified .