Sniff Test

Also available in PDF format: Sniff_Test.pdf  

 

What is a sniff test (chest fluoroscopy)?

The sniff test is a fluoroscopic exam used to check how the diaphragm (the muscle that controls breathing) moves during activities such as breathing normally and inhaling rapidly.
Your diaphragm normally moves down when you inhale, and up when you exhale. Both the right and left sides of your diaphragm should move in the right direction at the same time.
During the sniff test, the radiologist will observe how your diaphragm moves. You will be asked to "sniff" or quickly breathe in through your nose. An injury or abnormality resulting in paralysis of the phrenic nerve (the nerve responsible for diaphragmatic motion) can be detected in this manner.

 

How should I prepare?

No preparation is needed.

 

How is the examination performed?

Small amounts of X-rays are passed through the body. When a special X-ray detector is exposed to the absorbed X-rays, a detailed picture of the diaphragm is captured.
The radiologist or technologist will have you sniff or quickly breathe in through your nose and then take pictures of your diaphragm.
The procedure takes about 15 minutes.

 

What will I feel during the examination?

This exam is painless.

 

Who interprets the results and how do I get them?

A radiologist trained to interpret sniff tests will review the pictures and send a report to your doctor, who will give you your test results. The radiologist will not discuss the results with you. Based on the findings, you and your primary care doctor will decide the next step, such as treatment for a problem, as needed.