Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is an opacity obscuring the right heart border , with volume loss in the right lung . Cardiac size is normal . The lungs are clear . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
Right basilar opacity with volume loss in the right lung may represent atelectasis , however pneumonia can not be excluded . Recommend follow - up radiographs in 4 weeks is recommended to ensure resolution .