Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Left chest wall AICD device is again noted , unchanged with leads extending to the region of the right atrium and right ventricle . Midline sternotomy wires and mediastinal clips are again noted . The heart appears mildly enlarged . The lung volumes are low with mild basilar atelectasis . No convincing signs of pneumonia or CHF . No large effusion or pneumothorax . No free air is seen below the right hemidiaphragm . The bony structures are intact .
    OUTPUT:
    
Bibasilar opacities , most likely atelectasis , less likely pneumonia . Mild cardiomegaly .