Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild right middle lobe atelectasis , increased since the prior study , but similar compared to the radiograph from ___ . Mild linear atelectasis is present in the left lung base . There is no pleural effusion , pneumothorax , or pulmonary edema . The cardiomediastinal silhouette is stable . Indentation along the right trachea reflects known right thyroid nodule .
    OUTPUT:
    
Right middle lobe and left lung base subsegmental atelectasis .