Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Given the patient 's body habitus , evaluation is extremely limited . Frontal and lateral chest radiographs demonstrate chronic scoliosis and a mildly enlarged cardiac silhouette which is unchanged from prior radiographs . Low lung volumes make evaluation difficult , but a focal opacity in the left lower lung probably represents atelectasis . There is no pulmonary edema , pleural effusion , or pneumothorax .
    OUTPUT:
    
A left lower lung opacity probably represents atelectasis .