Earlier this spring I went for a PET scan. (Isn’t that a bit of a silly name? A sweet puppy-ish name for what can be an unnerving experience. See also: CAT scan.)
PET stands for Positron Emission Tomography, a scan that takes 3D images of organs and tissues. It’s often used to look for signs of cancer, spots that light up if they have higher metabolic activity, but it can also be used to detect issues of the heart or brain.
After I was diagnosed with neck cancer, in my 20s, I went for a PET scan every year.
The PET scan was my annual moment of truth.
After about a decade of clear scans, my wonderful otolaryngologist (ear-nose-throat doctor) said I was done: My annual scans could end. It was such a relief, a finish line of sorts.
But this year, I had a winter lung infection, followed by my first bout of Covid, and my pulmonologist noticed that a teeny lung nodule was a teeny bit bigger than before, and recommended a PET scan.
And I thought, Oh sure. That’s old hat. I know ALL about PET scans.
But hey — time has a way of making you forget things.
On the day of the scan, I realized I had forgotten exactly how the process worked.
I would have done a few things differently, if I had remembered all the steps.
So this is for anyone who is having a PET scan, and for future me, to remind myself what happens.
Keep in mind that this was was a specific PET scan looking for any concerns in the lungs. Your PET scan likely has different areas of interest and maybe even different reasons — ask your doctor to walk you through what to expect. This is just one patient’s experience, not medical advice.
The Big Questions
Does it hurt? No, not at all.
What’s the worst part? I had to lay still for 30 minutes while the scan was going on.
Really? That doesn’t sound too bad. It’s one of the easiest tests I’ve experienced. Actually, the real worst part is waiting for the results.
The Takeaways
Bring a book. I had to wait for an hour while the radioactive tracer circulated in my body, before the scan could happen. I completely forgot about the waiting.
Bring water. I couldn’t have any food 6 hours before the exam, but I could have water.
Consider a morning appointment. Then I would have skipped just breakfast.
Remember your other medications. If other medications need to be taken with food or on an empty stomach, that might affect when you want to schedule your appointment.
Bring a snack. I wish had I brought a favorite snack to eat immediately after the exam. I ended up at the nearby gas station with a Dunkin’ Donuts French cruller (the best of the donut lineup).
Wear comfortable clothes and no jewelry or metal accessories. This is a great day for sweatpants or lounge clothes.
Note: What follows is a recap of my PET scan, which may not be exactly how yours goes. Obviously, your doctor knows best what you need. Follow your doctor’s instructions. I am one unique patient, not a clinician.
Preparation
I was told:
Do not exercise rigorously 24 hours before the test.
Do not eat 6 hours before the test.
Water is fine. Lots of water is fine. (The PET scan requires an IV, and being well hydrated makes putting in the IV easier.)
Breakfast at the crack of dawn
My test was at noon. With no food allowed 6 hours before, I got up at 5:30 a.m. with plans to make my usual morning shake (banana, yogurt, coconut milk, ice, chocolate protein powder, peanut butter).
I forgot about my thyroid medication. Whoops! It’s ideally taken on an empty stomach 30-60 minutes before breakfast. That would have meant rising at 4:30 a.m.
Nope, that didn’t happen.
What can you do? It was one day.
Inside the PET scan trailer
Then I drove to the healthcare center, got checked in and led to a huge white trailer parked behind the center. I was surprised: Can the PET scan machine drive around? (I imagined the medical trailer chugging down I-95 to the next patient.)
It could, a healthcare team member told me, but this particulartrailer stays put.
The trailer had a lift, so we stepped onto a metal platform, closed the gate, and were raised up maybe 4 feet. A large door on the side of the trailer was open, reminding me of peering into a Barbie house.
I could see a small room on the right side with a padded patient chair, resembling a family room recliner; a middle room with a desk area and computers for the technicians; and a room on the left with the scanner itself — a long plank covered in sheets to lay on, and then a thick white donut-like hoop that the plank would slide into.
Source: Armor Mobile Systems has a super helpful summary of their mobile CT/PET trailers and all the features.
Hot Lab
I was directed to sit in a chair in the room on the right, which is apparently called the “Hot Lab.” This is where the radiopharmaceuticals are stored.
The magic of the PET scan involves a radioactive compound injected into your body.
Radioactive makes me immediately think of Chernobyl or other nuclear dangers, but radiation is not necessarily dangerous. (Much like the word “stress,” "radioactive” seems supercharged with risk.)
“Radiation is simply a type of energy. The most familiar form of radiation is visible light, like that produced from the sun or a light bulb. Other forms of radiation, such as X-rays and gamma rays, are used in a number of beneficial ways, including medicine.
“Natural radiation exposure comes from the earth in rocks and soil and from outer space in the form of cosmic rays. A small amount of radioactive material even exists naturally in our bodies. Every year, each person is exposed to this natural radiation and radiation from a variety of other sources, including household smoke detectors and color television sets. Air travel increases exposure to cosmic radiation due to the higher altitudes and less atmospheric shielding.”
I was given an IV in my arm, and then injected with the radiotracer.
(If you haven’t had an IV before, it requires a prick with a needle, but then once the IV is in, you can receive infusions, medications, etc. without being pricked every single time. Sometimes I can hardly feel needle that puts the IV in, and sometimes it feels like a sharp sting.)
The technician gave me a rundown of how the radiotracer will break down in my body quickly, because of the high half-life of the radiation (high school chemistry was vaguely coming back).
Then I was left to wait for an hour. They kindly gave me a heated blanket and propped up my feet in the recliner — no rigorous activity! I wished I had brought a book or my laptop to work. (Though perhaps work counts as rigorous activity?)
After an hour, I moved to the room on the left side of the trailer with the PET scan machine.
I laid down on the plank and they put a soft wedge under my knees, so my legs were elevated. (I think I would have been more comfortable without it, but you see what you think.)
They asked me if I was claustrophobic — no — and then told me the test would be about 30 minutes. I needed to be still.
I would take a nap, the technician told me.
Once they left the room, the plank started moving, sliding me gently into the donut hole. I could hear noise, but it wasn’t loud, more like light whizzing, nothing like the jackhammer sound of an MRI.
And then I waited. And waited. And waited.
I kept my eyes shut. It seemed better that way. I let my thoughts swim. What else was there to do but daydream?
After 30 minutes, the plank slid out, and the technician returned to lower the plank down and lead me out of the trailer.
That was all — done!
Final note
Then came the last phase: Awaiting the results.
My attitude about test results and life uncertainties is generally: It will be what it is. Worrying won’t change anything. Worrying only makes the experience much worse by taxing my thoughts and feelings.
A doctor should call within a few days with the results. This is the first time I can remember no one calling at all. I figured no news was good news, but it was still unsettling.
After a couple of weeks, I finally called the clinic and left a message for my doctor to please call me with the results. A nurse called me back and told me it was clear. The teeny lung nodules had no “uptake” in the tracer — likely something benign and not troublesome.
Whew!
I asked the nurse to please mail me a copy of the PET scan report. I like to read the full write-up and keep a copy in my records — I highly recommend always keeping your own paper copies. You can also scan them and have them easily available on your computer.
I hope this PET scan rundown is useful to you or someone else. If you’ve had a PET scan before, how was it for you? What would you add?
And if you have a scan of any kind coming up, I hope you have an easy and non-newsworthy test.
To our journeys, Brianne
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This was very interesting - thanks for all the details! I’ve had many MRIs and a few CT scans, but never a PET scan. The knocking and buzzsaw sounds of the MRI are truly terrible.
This was very interesting - thanks for all the details! I’ve had many MRIs and a few CT scans, but never a PET scan. The knocking and buzzsaw sounds of the MRI are truly terrible.