Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable chest radiograph demonstrates symmetric and well expanded lungs . The cardiomediastinal silhouette is stable in appearance when compared to prior study dated ___ , including a right aortic arch and descending right aorta . No focal opacity convincing for no pneumonia is identified . No overt pulmonary edema is seen . Probable left small pleural effusion is present . No air under the right hemidiaphragm is identified .
    OUTPUT:
    
No acute abnormality detected . Right aortic arch