Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a dense left upper lobe opacity extending from the hilum . There may be accompanying volume loss in the left upper lobe which is possibly reflected in mild relative elevation of the left hemidiaphragm compared to the right . There is no pleural effusion or pneumothorax . Elsewhere , the lungs appear clear .
    OUTPUT:
    
Dense left upper lobe opacity with suspected volume loss . Although this may reflect dense consolidative pneumonia , findings at least raise concern for the possibility of an underlying mass with associated pneumonitis as a possible alternative diagnosis . If pneumonia is suspected clinically , then short - term follow - up radiographs could be considered as follow - up management to show a trend toward resolution within a few weeks . a few weeks . Otherwise , particularly if pneumonia does not appear likely as the explanation clinically , then chest CT should be considered , preferably with intravenous contrast , if feasible .