Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided dual - chamber pacemaker device is noted with leads terminating in the right atrium and right ventricle . Heart size is difficult to assess given obscuration of the right heart border due to a small to moderate size right pleural effusion . The aorta is unfolded . There is no pulmonary edema . Right basilar opacity likely reflective of atelectasis is present . No left - sided pleural effusion is seen . There is no pneumothorax is identified though assessment of the lung apices is somewhat obscured by the patient 's chin projecting over this region . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Small to moderate right pleural effusion with right basilar atelectasis . Pneumonia is difficult to exclude , however , within the right lung base .