Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is normal . Mediastinal and hilar contours are within normal limits . Pulmonary vasculature is normal . Minimal blunting of the left costophrenic sulcus is unchanged from prior , likely reflective of a trace pleural effusion . No right - sided pleural effusion is present . There is no pneumothorax . There is minimal atelectasis in the left lung base . No acute osseous abnormalities present .
    OUTPUT:
    
Trace left pleural effusion , not substantially changed in the interval , minimal left basilar atelectasis .