So today was my second adventure in Nuclear medicine. I didn’t get any superpowers when I had my first experience with these guys, so I don’t have my hopes up this time around either.
With or without superpowers, I was feeling fairly relaxed about the whole procedure as I’ve been through it before. The big differences were this time, I (mostly) knew what to expect, and I brought a camera with me to take some pictures. Well, really I only got one decent picture, but it’s a good one…
Radioactive
You know they’re serious when the needle is delivered in a lead-lined steel tube. They sat this infront of me on a little cart then left for a while, allowing me ample opportunity to sneak a photo.
Inside the needle is something called Technetium-99m-MDP. The MDP part refers to the medical component, which is that it binds to living bone structure. The Technetium-99m part is the radioactive part. This has a gamma-decay half-life of about 6 hours – meaning that in about 6 hours, half of it has decayed emitting a gamma wave. Or particle. Or wavicle.
Technetium-99m decays into Technetium-99, which then has a half-life of over 200,000 years, emitting beta wavicles as it decays into Ruthenium-99. Something about this feels like it should be at least slightly unhealthy. But then, I’m not a doctor.
Having been suitably irradiated, I was then left to my own devices for the next 150 minutes, to allow the isotope to bind to my bones. The clinic was near enough to home that I could come back here to wait out the delay.
Another difference between my first radiological experience and this one, is that this time, I own a geiger counter! More specifically, I’ve built one into my home MCP project.
Over the past few months, it has been counting the background radiation. And I mean very background. Around here, it averages about 1.45 counts per minute – or in other words, the detector usually registers two counts for every three minutes or so.
Unlike the geiger counters you see on TV or movies, mine doesn’t click – that’s very annoying – I removed the clicker and put in a blinky light. So it blinks when the tiny sensor detects a gamma or beta wavicle.
Tiny sensor? You bet. It’s about half of a cubic centimeter in volume. About 2cm long and a quarter cm in diameter. Very small.
Anyways, the cool thing – as soon as I came in the front door I could see the thing blinking like crazy. Standing 2 feet from it, it was going off the chart! I reset the counter then pulled out my phone and recorded a little video of it.
In this video clip, you can see the counter (lower left corner of the lower LCD screen) starts at 1999, and the video clip runs until the counter passes 2200 counts. This happens in less than 45 seconds. The actual count is just under 300 cpm — more than two hundred times the normal background level here!
I was standing about 2 or 3 feet from the detector while filming that little clip. Pretty amazing to think that I was giving off so much radiation that I could drive the little sensor wild like that.
The actual imaging process was boring and I couldn’t take any pictures of their toys, they took away my camera and everything else while I was in The Machine. And now I’m just watching my geiger counter as it shows the steadily-decreasing radiation levels… with a half-life of about 6 hours, I’ll only have about 6% of my radiation left, when it hits the 24-hour mark.
Oh well, it was fun while it lasted.
