Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . The heart size and cardiomediastinal contours are normal . Lung volumes are low . Small opacity obscuring the left posterior costophrenic angle could represent consolidation or effusion . No pneumothorax .
    OUTPUT:
    
Small opacity obscuring the left posterior CP angle could represent consolidation or effusion . No cardiomegaly .