Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest . Mild cardiomegaly is unchanged . Aortic knob calcifications are unchanged . Again seen is enlargement of the main pulmonary artery . The lungs are clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute cardiopulmonary process . Unchanged enlargement of the main pulmonary arteries . Mild cardiomegaly is unchanged .