Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Uniform opacification of at least the medial subsegment of the right middle lobe is unchanged since the ___ study . The absence of air bronchograms is sometimes a feature of bronchial obstruction . A small right pleural effusion is stable . The left lung remains clear . Moderate cardiomegaly is stable . Left - sided pacemaker with single lead ending in the right ventricle is unchanged .
    OUTPUT:
    
1 . Overall , little change since the ___ study . No pulmonary edema with stable cardiomegaly . 2 . Stable appearance of right middle lobe opacification . If symptoms and radiographic abnormality do not improve within two weeks , further evaluation with contrast - enhanced chest CT is recommended to exclude bronchial obstruction .