Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Initial image demonstrates left mainstem bronchus intubation . Subsequent image demonstrates endotracheal tube in place with tip 3 .3 cm cranial to the carina . Initial image demonstrated complete collapse of the right lung though subsequent image demonstrates partial atelectatic collapse of the right lung with improving aeration . Left lung remains essentially clear . Moderate cardiomegaly is unchanged . Left hilar contour is normal . Right hilar contour can not be evaluated . No large pleural effusion or pneumothorax .
    OUTPUT:
    
Final image demonstrates appropriate positioning of the endotracheal tube with improved aeration of the right lung which was previously collapsed due to left mainstem intubation .