Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates low lung volumes , which results in bronchovascular crowding . There is a probable small left pleural effusion with adjacent atelectasis . Pneumonia can not be excluded . The cardiac silhouette remains unchanged . The aorta is tortuous . No pneumothorax .
    OUTPUT:
    
Probable small left pleural effusion with adjacent atelectasis . Pneumonia can not be excluded .