Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is mildly enlarged and is increased in size since the previous chest radiograph of ___ and probably since the more recent portable radiograph of ___ as well . Pulmonary vascularity is normal , and lungs and pleural surfaces are clear . Surgical clips are present in the thymic bed consistent with previous thyroid resection .
    OUTPUT:
    
Mildly enlarged cardiac silhouette may reflect mild cardiomegaly or pericardial effusion . No evidence of pulmonary edema or pneumonia .