Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Aorta is mildly tortuous . Prominence of the central pulmonary arteries is present bilaterally . Lungs are slightly overexpanded but grossly clear except for focal linear atelectasis versus scar at the left lung base . There are no pleural effusions or acute skeletal findings .
    OUTPUT:
    
Focal linear opacity in left lower lobe is a very nonspecific finding , but linear atelectasis can be observed in the setting of pulmonary embolism , the clinically suspected diagnosis provided in the history for this exam . With this in mind , further evaluation with CT pulmonary angiogram should be considered to more definitively evaluate for the possibility of pulmonary embolism given the clinical suspicion for this entity .