Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . There is slight elevation of the left hemidiaphragm , not significantly changed since prior chest x-ray . Left basilar opacity obscuring the left costophrenic angle and retrocardiac opacity are most likely due to atelectasis . Elsewhere , the lungs are clear . Cardiomediastinal silhouette is within normal limits . No acute osseous abnormality is identified .
    OUTPUT:
    
Streaky left basilar atelectasis ; otherwise , no acute cardiopulmonary process .