Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The aorta is moderately tortuous . Otherwise , the mediastinal and hilar contours appear unchanged . There is a trace pleural effusion on the right . A trace pleural effusion is difficult to exclude on the left side . Fissures are slightly thickened . Aside from vague opacity suggesting minor atelectasis along posterior costophrenic sulci , the lungs appear clear without findings suggestive of parenchymal edema . Mild degenerative changes affect the thoracic spine .
    OUTPUT:
    
Trace right - sided pleural effusion , at least on the right side . Suspected mild posterior basilar atelectasis , probably bilateral . No evidence of pulmonary edema .