Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low bilateral lung volumes . A tracheostomy tube is present as is a right PICC line . Unchanged diffuse bilateral pulmonary opacities when compared to the most recent prior radiographs however increased when compared to the chest radiograph dated ___ . A superimposed infection can not be excluded . No pleural effusion or pneumothorax identified . The appearance of the cardiomediastinal silhouette is unchanged .
    OUTPUT:
    
Persistent diffuse bilateral parenchymal opacities for which a superimposed infection can not be excluded .