Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There may be subtle opacity in the retrocardiac region but there has been significant interval improvement since recent CT of the chest . There is no new consolidation . The cardiomediastinal silhouettes within normal limits . No acute osseous abnormalities . Right PICC is identified . The tip is not clearly delineated on the frontal view but is in the region of the lower SVC on the lateral view .
    OUTPUT:
    
Significant improvement in the appearance of the lungs with perhaps mild residual retrocardiac opacity .