My doctors told me they wanted me to have a scan of my thyroid to try to help work out why I’m currently experiencing hyperthyroidism. I had a letter inviting me to a technetium thyroid scan, which also specified that I was not allowed to eat seafood or take vitamin supplements containing iodine for 48 hours before the scan. Easy enough! But what is it like to have a radioactive thyroid scan? I’ve written about the whole experience below…
Radioactive Thyroid Scan – My Experience
Before The Thyroid Scan
I arrived at the Department Of Nuclear Medicine at 8.20 on Monday morning, and my immediate thought was that they probably have the most badass name of any hospital department. I got signed in, and waited for my name to be called. The chairs in the corridor were all arranged at two metre intervals, with tape marks on the floor to show safe distancing.
The Technetium Injection Process
Predictably, when my name was called it was pronounced wrong, but that broke the ice with the technician doing my injections, who was lovely. I was taken to a side room to have an injection of a radioactive isotope called Technetium, which sounds like a made-up element from the Marvel universe, but is apparently a real thing. They used to use radioactive iodine for these kinds of scan, but this has now been mostly replaced with technetium, which gives a lower radiation dose.
Before the injection, I was asked some questions. The technician checked whether I have claustrophobia and whether I was able to get up and down from a couch, which I thought was good practice checking for hidden disabilities. Then there was the usual “you’re a woman so please sign on the dotted line that you’re not pregnant” and they checked my identity one last time.
The injection itself was nothing at all! They jab you with a tiny needle, flush the line with saline solution, then give you the technetium injection. Because it’s radioactive, the needle has a little tungsten jacket to protect the technician’s eyes and fingers from the cumulative effect of giving multiple radioactive injections every day! Then they flush the line with saline again.
Before The Gamma Camera Scan
Once you’ve had your injection, you wait about twenty minutes before your scan. I was put in a little side room for radioactive people to wait, because you’re actually emitting gamma radiation during this time. You would never know it at all – you honestly can’t feel a thing! The effective radiation dose of a technetium thyroid scan is about 3.2 millisieverts (mSv) – the average annual dose from background radiation in the UK is 2.7 mSv. So it sounds like a lot, but actually if you live in Cornwall, your average annual dose of radiation is 6.9 mSv, due to the high levels of radon in the ground in Cornwall. And the annual limit of radiation exposure for nuclear industry workers is 20 mSv – so when you put it in context, it doesn’t sound so bad. None of us would worry about spending six months in Cornwall! (Unless you’re a city kid, I guess…)
After twenty minutes, I was called in to have my scan, in a machine called a gamma camera, or scintillation camera. Here’s a picture of the one I was in:
The Technetium Thyroid Scan Itself
I was asked to have a couple of sips of water, take off my necklace and face mask, and lie on the bed part of the gamma camera machine. Then the panels that you see on the left in the picture above swiveled so one was above my head and one below. They lower the panels until they’re very close to your head – the one above me was almost touching my nose!
The process of taking the pictures was weird because you can’t actually tell that anything is happening at all. There’s no noise like in an MRI scanner – you literally just lie there feeling a bit silly. Each picture took 1 – 5 minutes and at one point they reconfigured the scanner to get a close up of my thyroid gland. Then it was done!
My Experience Of Technetium Thyroid Scan
Overall, this was a really easy procedure. Anything that involves radioactive material can feel a bit scary, but it was totally painless, easy, and comfortable. If you are claustrophobic, you may not enjoy the experience of the scan itself as the machine gets so close to your face, but it’s better than an MRI scan because the machine is open at the sides, so you’re not trapped in a tube, it’s much quieter, and the scans are taken much much more quickly, so you don’t have to spend much time in the machine at all. Plus the staff were very aware that it could be uncomfortable for claustrophobic people and asked if I was okay with the scan etc. while it was ongoing.
What happened after my thyroid scan?
It took a long time to get the results of my technetium thyroid scan and get a diagnosis, but I did eventually get there… Click here to find out what happened next.