Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Previously seen mild pulmonary vascular congestion has resolved . A 4 mm nodular opacity at the medial right lung base is seen only on the frontal projection and could be superimposed normal thoracic structures , although a pulmonary nodule is not excluded . The lungs are otherwise clear . The heart size is normal . Deviation of the trachea to the right at the level of the thoracic inlet is not significantly changed , suggestive of enlargement of the left thyroid lobe . There are no pleural effusions . No pneumothorax is seen . Multilevel degenerative changes of the thoracic spine are noted .
    OUTPUT:
    
1 . No acute cardiac or pulmonary finding . 2 . 4 mm nodular opacity projecting over the right medial lung base , possibly secondary to superimposition of normal thoracic structures , although a pulmonary nodule is not excluded . Further evaluation could be performed with a dedicated PA radiograph of the chest .