Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A frontal semi-upright view of the chest was obtained portably . Low lung volumes result in bronchovascular crowding . Slightly increased bibasilar opacities likely represent atelectasis . There is no pleural effusion or pneumothorax . No acute osseous abnormality is identified . There is no free air under the diaphragm .
    OUTPUT:
    
Bibasilar opacities are likely atelectasis given low lung volumes , but aspiration , early infection or early infarction are not excluded in the appropriate clinical setting . If clinically indicated , conventional frontal and lateral radiographs might be helpful for further evaluation .