Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is subtle increased opacity projecting over the left lung apex overlying the clavicle and posterior left sixth rib , as on prior . There is blunting of the left lateral costophrenic angle raising possibility of small underlying effusion . Retrocardiac opacity may also be due to atelectasis or infection . There is moderate cardiomegaly , unchanged . Median sternotomy wires and left chest wall single lead pacing device is again noted .
    OUTPUT:
    
Persistent left apical opacity for which two view chest is suggested when patient is amenable . Left basilar opacity likely due in part to an effusion and atelectasis . Infection is not excluded .