Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A tracheostomy tube is in place . Compared with the most recent chest x-ray from ___ at 23 :23 , there is relatively extensive new opacity in the left lower zone , with retrocardiac density , obscuration of the left hemidiaphragm and hazy opacity extending along the left lower chest wall . There is a very slightly coarsened appearance to the vessels / parenchymal markings in the left upper zone , which is new , but no focal consolidation or evidence of CHF . The cardiac silhouette is also slightly larger . Aside from minimal atelectasis at the right lung base , the right lung and costophrenic sulcus are clear .
    OUTPUT:
    
Prominent new opacity at the left lung base , consistent with left lower lobe collapse and / or consolidation . An element of pleural fluid would be difficult to exclude .