A lung scan is performed to evaluate air distribution and blood flow within the lungs. Patients with shortness of breath or chest pain may receive a lung scan to evaluate or rule out obstructions in blood vessels in the lungs.

Images from a normal lung ventilation scan showing wash-in and wash-out of radioactive Xenon gas.

Your Medical Test

The lung scan is performed in two parts. First, the patient breathes in radioactive gas (133-Xenon) for approximately 1.5 minutes and breathes it out for about 3.5 minutes. An injection of 99m-Technetium is then given in a vein in the patient's arm. Several images are then obtained by rotating the scanner’s camera around the patient, who is lying on a bed-like platform.

Technetium-99 is a widely-used isotope in Nuclear Medicine. It has a short half-life (6 hours) so that the material soon leaves body tissues. It emits gamma radiation (high energy photons) of appropriate energy for detection by gamma cameras. The technetium is attached to a pharmaceutical agent (MAA) that localizes in blood vessels in the lungs. No allergic reactions are experienced with this test.

How to Prepare for a Lung Scan

• You can eat or drink before the injection and scans.
• You should continue to take any regularly prescribed medications.
• You should drink plenty of liquids and should empty your bladder regularly between the injection and the scan.
• Your should wear comfortable clothes for the procedure. The technologist will need to be able to inject the isotope in a vein at the elbow.
• How to Schedule a Lung Scan
• Your doctor will schedule the Lung Scan, then notify you of your appointment time. If you wish to change the appointment, please call Central Scheduling (305.8080) from 8 a.m. to 5 p.m. Monday through Friday at your earliest convenience. If you have any questions about the procedure, please call Nuclear Medicine (305.9070).

When and Where Should I Go?

You should arrive at Patient Registration at UT Medical Center at least 30 minutes prior to your scheduled scan.

1. Take the UT Medical Center exit off Alcoa Highway.
2. Follow the entrance ramp, which will end at the medical center entrance.
3. Follow the overhead sign for Hospital Patients, and turn on the third road on the right (leads to Circle Drive).
4. To park, take an immediate right into the Visitor Parking Lot. Enter the hospital at the entrance marked Main Entrance on the front circle.
5. To drop off a patient, follow the circular drive to the Main Entrance. Drop off the patient, then park in the Visitor Parking Lot, which will now be on your left.
6. Patient Registration is located in the Main Entrance lobby, across from the Information Desk.

After registering, you will proceed to Nuclear Medicine and notify the receptionist of your arrival

When Will I Receive the Test Results?

Images are reviewed by a doctor at the end of the day. When all images have been viewed, a report is prepared within 48 hours. Your physician may receive a faxed interim report immediately after the images have been viewed. Once your doctor has reviewed the report, your doctor will inform you of the test results.

Division of Nuclear Medicine
Department of Radiology
The University of Tennessee Medical Center
1924 Alcoa Highway
Knoxville, TN 37920-6999
865.305.9070