Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 04 : 50 is submitted .
    OUTPUT:
    
Low lung volumes . Interval appearance of retrocardiac consolidation with volume loss suggestive of left lower lobe collapse . Pneumonia can not be excluded . No obvious edema . No pneumothorax . Right subclavian PICC line is unchanged in position . Interval removal of the feeding tube . Heart remains enlarged . Mediastinal contours appear widened , but this is likely projectional given patient positioning .