Wednesday, 11 September 2013

Becoming Spiderman

I am scheduled for a full body neuromuscular bone scan next Monday. This is a nuclear process where they inject a radioactive dye, also called a "tracer", into your arm and then wait until it circulates through your body and "binds" to the bones. In a normal bone scan, the tracer moves evenly through the body. In an abnormal bone scan the tracer accumulates in the damaged bone tissue and becomes highly visible on special camera designed to pick up the radiation from the tracer.

This is a lengthy procedure. First, you have to arrive early, a half hour ahead of your appointment. My appointment is at 9:00 AM, so that means 8:30 for me. That way they can prepare me for the injection. That preparation includes making sure I have emptied my bladder and bowels, as the dye likes to accumulate in the body's waste systems. Then they clean your arm, where they will inject the radioactive dye, and then they inject this stuff into you, at which point you become ever so slightly radioactive.

Once the dye is injected and the medical team is certain you are not going to have a negative reaction to the tracer, you simply go and wait for a few hours. During the wait they ask you to drink two or three glasses of water to wash out any of the tracer that does not collect in your bones. Then, once again, you have to go pee to empty your bladder so they can see through it to the pelvic bones, otherwise the tracer in your bladder would glow and obscure the view.

It's an interesting thing this radioactivity. They tell you the dose is so low that it is harmless. The only concern they really have is that some people have a reaction to the solution with the radioactive isotope in it; not the isotope itself but the overall solution. However one of the warnings that you get when doing this type of thing is to "flush the toilet right away and thoroughly wash your hands with soap and water" after going to the bathroom. It makes you wonder just how much radiation there is in the isotope.

All of this is being done in an effort to determine why my shoulder is hurting so much. I am pretty sure I know what they are going to find. I think they will find a stress fracture in my arm, right beneath the shoulder joint. I think it fractured with I fell while having my heart attack. That's my guess. So off I go on Monday to get radioactive. Too bad it's not a radioactive spider doing the injection. At least then I might become Spiderman.


  1. I had that dye last week and they gave ma a card to show the USA customs if I went to the states. So I guess the radioactivity stays for about a week. I hope they find the problem with that shoulder.

  2. The isotope is almost certainly Technetium-99m (m meaning metastable). It's produced from radioactive molybdenum-99, and the nucleus of Tc-99m quickly* rearranges itself to Tc-99, producing gamma rays as it does so. In other words, after a couple of hours your skeleton is X-raying your body from the inside out. Technetium also would be recognized by the body as essentially being manganese, an essential trace element found mainly in the - you guessed it - bones.

    *The half-life of Tc-99m is a hair longer than 6 hours. Thus, after one day 6.25% of the dose remains; two days, 0.4%; five days, one-millionth. From there, the decay chain is Tc-99 (long lived: 211,000 year half-life), then ruthenium-99 (stable). None of the four elements named is chemically toxic to the body, but if you like the medical staff conducting your test, flush that toilet quickly and help keep their cumulative radioactivity doses in check :)

  3. Excellent explanation Dan. But then again, why would I expect less from you? Although I prefer a "glow in the dark" metaphor if possible.