Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . The cardiac , mediastinal and hilar contours appear within normal limits . There is no pleural effusion or pneumothorax . Streaky opacities at the left lung base suggests minor atelectasis . A oval nodular opacity projecting over the left upper lung is of uncertain significance . There is a moderate hiatal hernia .
    OUTPUT:
    
1 . Possible pulmonary nodule in the left upper lung . When clinically appropriate evaluation with repeat PA and bilateral oblique views is recommended to see whether the opacity may persist or perhaps represent an artifact , versus consideration of chest CT . 2 . Suspected minor left basilar atelectasis . 3 . Moderate hiatal hernia .