The bone scan is relatively simple, and the pictures that you get back are amazing! It's really cool to see your entire body in skeletal form!
You do get an injection of dye so the images show up. Any place that has inflammation happening will "light up", or show as black on the images. The scan also shows degeneration in bone, and can even pick up cancer tumors! It's wild. The entire test took about 4 hours. After the injection you have to wait 2 hours for it to circulate through your body. Then the images are taken. You spend the test part lying on a flat table while the scanner moves overtop of you.
I was given the test because my rheumy was suspicious of RA as well. I came back clean! You can have RA with negative blood work too. If a rheumatologist can do a physical exam of your joints, they can determine without blood tests if you have RA.
For Lupus, it's called a Lupus blood panel. I'm not certain of every test that is done, but here's what I do know... CBC, ANA, ESR(sed rate), Compliment levels, APS (antiphospholipid syndrome), Anticardiolipin antibody, urine. I'm sure there are more. But if you google Lupus blood panel, I think you come up with some hits.
Lupus and Fibro show up together more often than not. They're like cousins. Which is why it's so hard to tell which one is flaring. The symptoms are near identical. But Lupus can kill ya and Fibro can't (although it feels like it could some days).
Let me know what you learn okay. I'm interested!