Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The left hemidiaphragm is elevated . The medial left hemidiaphragm is partially obscured by a rounded opacity , which could represent atelectasis but can not exclude a mass lesion . The lungs are otherwise well expanded and clear . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is unremarkable . Degenerative changes are noted throughout the spine .
    OUTPUT:
    
Partial obscuration of the left hemidiaphragm medially by a rounded opacity , which could represent crowding of vessels from adjacent diaphragmatic elevation , but can not exclude a mass lesion . Recommend nonurgent CT to exclude possible mass .