Exams and Treatments



Left-to-Right Shunt Studies


Detect and quantify any abnormal opening or passage that allows oxygen-poor blood to move from the left heart cavities to the right heart cavities without going through pulmonary circulation.


Approximately 3 hours

  • Take your medication as per usual. There is no specific preparation for the exam.
  • Have an updated list of your medications on hand when you make the appointment and when you come in for the exam.
  • Inform the care team if you are pregnant, may become pregnant, or are currently breastfeeding.

First, the technologist injects a product that binds to the red blood cells and prepares the blood to receive the radioactive tracer. This injection is followed by a waiting period of approximately 30 minutes.

Patients then lie down on a stretcher so that the doctor can insert a catheter in a jugular vein (in the neck). The patient is then slid under camera, as the radioactive tracer must be injected at the same time as the images are taken. This takes place over a short period (1 minute).

The team then conducts a left ventricular function study (see description of this exam).

Follow-up and side effects 
  • You can resume your normal activities after the scan. The exam result is sent to your treating physician.
  • If you are planning a trip outside of the country in the weeks following the exam and will have to go through AIR OR GROUND customs, it is important to advise the technologist. The presence of a radioactive tracer in your body may be detected at customs. You will therefore be given a document to confirm that you underwent a nuclear medicine exam.
Department of Radiology and Nuclear Medicine