A SPECT scan is properly called a Single Photon Emission Computed Tomography scan.
A Single Photon Emission Computed Tomography (SPECT) scan is a type of nuclear imaging test that shows how blood flows to tissues and organs and in my case we were interested in seeing how the blood was flowing in my brain.
Why did I have a SPECT scan?
The reason we wanted to see how the blood was flowing in my brain was due to the fact that I had suffered from Subtle Traumatic Brain Injury affects since a car accident in March 2000. After the accident I couldn’t remember people when I met them, forgot most technical terms that I had worked with for decades, looked at a resume and didn’t know what do with it (and I was a recruiter) and so on and so on. My life was a mess. And, over the years, I had suffered various head traumas that had resulted in me losing consciousness more than 11 times. hehehehe there are a few stories there.
How did my SPECT scan work?
A SPECT scan integrates two technologies to view my brain body: computed tomography (CT) and a radioactive material (tracer). The tracer is what allows doctors to see how blood flows to tissues and organs.
Before the SPECT scan, I was injected with a chemical that is radiolabled, meaning it emits gamma rays that can be detected by the scanner.
The SPECT scan differs from a PET scan in that the chemical stayed in my blood stream rather than being absorbed by surrounding tissues, thereby limiting the images to areas where blood flows. SPECT scans are cheaper and more readily available than higher resolution PET scans.
The computer collected the information emitted by the gamma rays and translated them into two-dimensional cross-sections. These cross-sections were then added back together to form a 3D image of your brain.
What did my SPECT scan show?
My SPECT scan was used to view how blood flows through arteries and veins in my brain. Over the years various tests have shown that a SPECT scan can be more sensitive to brain injury than either MRI or CT scanning because it can detect reduced blood flow to injured sites. And seeing the reduced blood flow is what this was all about.
How did the tracer work?
The radioisotopes used in the SPECT to label tracers are iodine-123, technetium-99m, xenon-133, thallium-201, and fluorine-18. These radioactive forms of natural elements will passed safely through my body and could be detected by the scanner. Various drugs and other chemicals can be labeled with these isotopes without changing their properties.
Who performed my SPECT scan?
My SPECT scan was performed by the very friendly folks in Nuclear Medicine at Sunnybrook Health Sciences Centre here in Toronto, Ontario. A specially trained nuclear medicine technologist performed the test. A nuclear medicine doctor reviewed the images and wrote a report of the findings and this was then provided to my doctors.
How did I prepare for the SPECT scan?
There was really nothing to do except turn up at my appointment on time wearing comfortable clothing especially a short sleeve shirt. There was no need to fast or avoid certain foods or beverages. I was there for a couple of hours.
What happened during the SPECT scan?
There were a number of steps.
First I was given an injection of a small amount of radioactive tracer while I was standing in front of an x-ray. I forgot to ask what the x-ray was being for because I was more focused on the guy getting ready to inject the tracer into me. Yikes! A needle. And he was in training so I’m not sure who was more nervous.
I was then asked to wait in the waiting area for about 20 minutes until the tracer reached my brain.
After 20 minutes I was taken into the room with the SPECT scan and asked to lie on the scanner table. A special camera with 3 lens was position around my head. The camera was positioned very close to my head and then rotated around my head. I had to remain as still as possible – for 20 minutes – so that the machine could get accurate pictures.
Once the scan was complete, I got up and left. That was it. I was told to drink plenty of fluids to flush out any tracer left in my body.
Were there any risks?
Of course but minimal. The amount of radiation your body is exposed to is less than you receive during a chest X-ray or CT scan. Women who are pregnant or nursing should not undergo a SPECT scan.
What about my results?
The nuclear medicine doctor reviewed my images in a few days, wrote a short report and then my referring doctor picked them up. We reviewed the results and mapped out a course of action. I’ll talk write about that later.
Useful SPECT Scan links
If you are interested in learning more about SPECT – Single Photon Emission Computed – scan I recommend the following websites:
www.radiologyinfo.org: is a website designed to answer your questions related to the many radiologic procedures and therapies available to you and your family. The Web site provides you with information whether you’re preparing for a baseline mammogram, learning more about your child’s x-ray, or researching radiation oncology (cancer therapy) procedures.
www.nlm.nih.gov/medlineplus/diagnosticimaging.html: Diagnostic Imaging at MedlinePlus provides a wealth of information. MedlinePlus brings together authoritative information from NLM, the National Institutes of Health (NIH), and other US government agencies and health-related organizations.