Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A frontal AP upright view of the chest was obtained portably . The examination is suboptimal due to poor penetration and patient body habitus . Lung volumes are slightly low , resulting in bronchovascular crowding . The lungs are grossly clear aside from mild bibasilar atelectasis . There is no large effusion or pneumothorax . Cardiac and mediastinal silhouettes are unchanged allowing for differences in technique . Apparent widening of the mediastinum is likely due to portable technique and low lung volumes . Hilar contours are normal . No acute osseous abnormality is identified on this limited study .
    OUTPUT:
    
1 . Limited study . No acute intrathoracic process identified . 2 . Apparent mediastinal widening is most likely due to portable technique and low lung volumes . If further evaluation is needed , conventional radiographs could be performed with PA and lateral views .