Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are again noted . There is persistent blunting of the left costophrenic angle suggesting an effusion . Increased interstitial markings throughout the lungs are similar compared to prior , likely due to combination of atelectasis in the setting of low lung volumes and superimposed edema . The cardiomediastinal silhouette is stable . Dense atherosclerotic calcifications noted at the aortic arch . Median sternotomy wires are intact . Linear radiopaque density projecting over the right upper extremity .
    OUTPUT:
    
No significant interval change since yesterday 's exam . Linear opacity projecting over the right upper extremity , potentially a PICC or external structure to be correlated clinically .