What is a SPECT-CT scan? 

A SPECT scan is commonly called nuclear medicine or molecular imaging. A SPECT-CT scan is a powerful imaging test that combines two technologies: SPECT (Single Photon Emission Computed Tomography) and CT (Computed Tomography). SPECT shows how your organs and tissues are working, while CT provides detailed images of their structure. By combining both, SPECT-CT offers a comprehensive view helping doctors diagnose a wide range of conditions with greater accuracy and confidence. 

 

Understanding your SPECT-CT scan

Doctors may request a SPECT-CT scan to investigate symptoms, monitor known conditions, or guide treatment. Common reasons include: 

  • Unexplained bone pain or injury 
  • Suspected infection or inflammation 
  • Assessment of blood flow to the heart or brain 
  • Cancer diagnosis, staging, or follow-up 
  • Evaluation of organ function (e.g. kidneys, thyroid, liver) 

 

Before your SPECT-CT scan

  • Most SPECT-CT scans require little preparation, but our booking specialists will let you know if you need to fast, arrive early, or adjust medications.  
  • You may be asked to drink extra water or avoid certain medicines before your scan. 
  • As with conventional CT, you may be required to have an injection of x-ray contrast. There is a very small risk of allergy, and you will be asked to complete a questionnaire and consent form before any injection is given. 

 

On the day of your SPECT-CT scan

  • When you arrive, please check in with reception. We'll make sure your details are correct and ask you to complete any appropriate consent forms. 
  • You will be taken to a private room where your technologist will explain the procedure and you can ask any questions you may have. 
  • You will be asked to change into a gown, and we will give you somewhere safe to keep your belongings. 

 

During your SPECT-CT scan

  • You’ll receive a small injection of a radioactive tracer into a vein in your arm. This highlights how your body is working and is usually well tolerated, with no side effects. 
  • After the injection we may perform the imaging straight away, or you may need to wait for a short time to allow the tracer to circulate. 
  • You’ll lie on a cushioned table that moves through the scanner. The machine may come close to your body, but you shouldn't feel enclosed, and you can speak to the technologist at any time. 
  • The scan is painless, but you’ll need to stay still and may be asked to hold your breath briefly. 
  • Scans take approximately 30 minutes, depending on the area being examined.
  • Additional images may be required after your images are reviewed.

 

After your SPECT-CT Scan

  • There are usually no restrictions after your scan, and you can return to normal activities. 
  • You will need to avoid prolonged contact with anyone who is pregnant and small children (under 18 years old) for 12 hours afterwards. 

 

Results

  • The images taken during the examination are interpreted by one of our team of specialised radiologists. 
  • The results of your SPECT-CT scan will go to your referring doctor after a detailed report has been written.  
  • Your doctor will discuss the important findings and next steps with you. 

Frequently asked questions

SPECT-CT is especially useful for: 

  • Detecting bone, joint, and soft tissue problems 
  • Assessing heart, brain, and organ function 
  • Diagnosing and monitoring cancers, infections, and injuries 
  • Planning and monitoring treatments, including theranostics (where diagnosis and therapy are combined in a single procedure).  

SPECT-CT is considered a very safe imaging procedure for most people. The scan uses a small amount of radioactive tracer which is generally well tolerated and leaves the body quickly. The level of radioactivity is about the same as a standard x-ray, and the radiation dissipates within a few days. Most people experience no side effects, and the scan itself is painless.

The scanner’s large opening and short length mean you are unlikely to feel enclosed. If you are anxious or think you might feel claustrophobic, please let us know - calming medication can be arranged if needed.

These examinations may not be suitable for pregnant women. The benefit versus risk should be discussed between your specialist and our SPECT Radiologist. 
 
Women who are breastfeeding and people who are caring for small children may need to make special preparations after the test to stop breastfeeding for a short time and to avoid close contact with young children due to the small amount of radioactivity released for a while after the test. Patients should discuss this with their referring doctor or the SPECT-CT department for more information.

Our Remuera clinic features the Southern Hemisphere’s most advanced analogue SPECT-CT, delivering sharper images and faster scans, therefore a better result for patients.

A support person may accompany you to your appointment but typically cannot enter the scan room.

It is important that we know as soon as possible if you are unable to make your appointment as your injection is prepared specifically for you and can only be used on the day it is prepared. This special radioactive tracer cannot be kept overnight, it only remains active for a short amount of time. You may be charged for the injection if you do not inform us that you will not be attending your appointment prior to the day.

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