Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A portable frontal chest radiograph demonstrates unchanged moderate cardiomegaly and right hemidiaphragm elevation . There is an unexplained left basal abnormality , which may represent atelectasis , but is not well evaluated . There is probably no pneumonia , but conventional frontal and lateral chest radiographs would be very helpful in further evaluation . No pneumothorax or large pleural effusion .
    OUTPUT:
    
Probably no pneumonia , but conventional frontal and lateral chest radiographs would be very helpful .