Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Semi-upright portable view of the chest demonstrates normal lung volumes . There is no left pleural effusion or pneumothorax . Hilar and mediastinal silhouettes are unchanged . Heart size is normal . Left costophrenic angle is not fully imaged ; however , pleural density involving the left lateral hemithorax in the lower lobe is longstanding and likely represents pleural thickening and / or effusion .
    OUTPUT:
    
No evidence of pneumonia . Left lower lobe pleural density likely represents thickened pleura and / or effusion .