Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild cardiomegaly and cardiomediastinal contours are similar to prior . Lung volumes are low . Increased left base opacity is likely related to large hiatal hernia . Vague heterogeneous opacity in the right upper lobe is similar to prior , likely residual scarring . No pneumothorax or substantial pleural effusion . Large hiatal hernia is similar to prior .
    OUTPUT:
    
1 . Large hiatal hernia . On this single projection , it is difficult to exclude an adjacent left lower lobe abnormality , and standard PA and lateral chest radiographs are suggested for this purpose when the patient 's condition permits . 2 . Mild cardiomegaly .