Final answer:
A chest radiograph can rule out acute aortic syndrome.
Step-by-step explanation:
The laboratory study that may rule out acute aortic syndrome is a chest radiograph. A chest radiograph, also known as a chest X-ray, can help evaluate the size and shape of the aorta, detect any abnormalities or dissections, and rule out other possible causes of chest pain or symptoms related to acute aortic syndrome.