Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a mildly tortuous thoracic aorta , with aortic arch calcifications noted , unchanged from prior ; the remainder of the cardiomediastinal silhouettes are stable and within normal limits . The bilateral hila are unremarkable . A rounded opacity at the left lung base measures approximately 7 mm , not clearly seen on the lateral projection , and not apparent on prior radiographs . The lungs are otherwise clear . There is no evidence of pulmonary vascular congestion . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
1 . 7 mm left lower lung rounded opacity , not seen on prior exams or on lateral projection , possibly a nodule . Recommend repeat PA and lateral chest radiograph for further evaluation . 2 . Otherwise , no acute cardiopulmonary process .