Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a small equivocal opacity at the left lung base , could be atelectasis . The right lung is clear . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette , hilar contour and pulmonary vasculature are normal . The underlying osseous structures are unremarkable .
    OUTPUT:
    
No definite acute cardiopulmonary process . A small equivocal opacity in the left lung base , could be atelectasis . However , if clinical concern remains high for infectious process , PA and lateral chest radiograph could be obtained to further assess .