Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates well expanded , clear lungs . The small right pleural effusion seen on CT of the abdomen and pelvis from the same day is not visualized on this radiograph . Cardiomediastinal and hilar contours are unremarkable . No pneumothorax . No free air beneath the right hemidiaphragm .
    OUTPUT:
    
1 . Known small right pleural effusion seen on CT of the abdomen and pelvis from the same day is not visualized on this radiograph . 2 . No free air beneath the right hemidiaphragm .