Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild elevation of the left hemidiaphragm is unchanged from multiple prior studies . There is likely a small left pleural effusion . Ill - defined airspace opacity in the right lung base may represent atelectasis or early pneumonia , depending upon the clinical setting . There is no pneumothorax or pulmonary edema . There is stable cardiomegaly and unchanged fractures of the top 2 sternotomy wires .
    OUTPUT:
    
1 . Ill - defined airspace opacity in the right lung base may represent atelectasis or pneumonia , depending upon the clinical setting . 2 . Probable small left pleural effusion . 3 . Stable chronic elevation of the left hemidiaphragm and mild cardiomegaly .