Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left basal opacification may represent effusion or atelectasis . Low lung volumes continue to be seen . ET tube is in appropriate position and unchanged . Right upper central venous line is unchanged in appropriate position , and a gastric tube traverses past the diaphragm and ends outside the view of the chest radiograph . The cardiac silhouette is unchanged , and no focal consolidation or pulmonary edema is seen .
    OUTPUT:
    
Stable position of lines and support devices . Left basal opacifaction may represent atelectasis or effusion .