Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were reviewed . Compared to the most recent prior study of ___ , minimal increase in radiographic denisty and subtle loss of vessel contours in the left lower lob could represent developing pneumonia . There is no pulmonary edema , vascular congestion , pleural effusion or pneumothorax . The heart size is normal and calcification of the aortic knob is unchanged .
    OUTPUT:
    
Minimal increase in radiographic denisty and subtle loss of vessel contours in the left lower lobe could represent developing pneumonia which should be confirmed on short term radiographic follow - up .