Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lower lung volumes seen on the current exam with secondary crowding of the bronchovascular markings . Opacity at the right cardiophrenic angle is likely due to patient 's known hiatal hernia . Retrocardiac opacity silhouetting the medial hemidiaphragm and descending thoracic aorta is likely due to a combination of atelectasis and effusion . Superiorly the lungs are clear . Cardiomediastinal silhouette is stable . PEG tube identified projecting over the abdomen .
    OUTPUT:
    
Lower lung volumes without definite superimposed acute cardiopulmonary process . Retrocardiac opacity likely combination of atelectasis and effusion .