Please, please are there any radiologists or orthopaedic experts who can answer a question for me?

[Desperatelisteningtorain]

How specific can a CT scanner be when looking at an area for imaging? I.e. if you need two vertebrae of the lumbar spine for example, can you do that, or can the machine only calibrate the whole lumbar spine? I know it must be programmable by size of patient but I'm not sure how much further it can be drilled down.

I'm besides myself as my toddler has an essential CT scan due for major surgery but he also might be at a much higher than usual risk for cancer due to another condition. As it is the online calculators are giving me a 1 in 300ish chance of childhood cancer based on the dose assumed by the study, and that's not even taking into account his additional vulnerability, but I think that dose could be significantly reduced if the machine can be more specific.

I know the projections go on the no threshold model which is disputed by some, but it is accepted by all major health authorities so of course it's made me concerned. We have no choice though.

I'm here worried absolutely sick about it.

Have you talked to his doctors about your concerns? They won't want to give him more radiation than can be helped. Sometimes you have to balance the risks and accurate scanning is clearly required. Dh works with radiology systems, the information he has puts the risk at 1 in 1000 and yes apparently it can be localised closely. Radiation used for lumbar x-ray is much higher - which is why it isn't done so much nowadays. It's possible the figures you've seen relate to radiation exposure through x-ray.

Yes - unfortunately it's essential because the surgery is absolutely necessary (he isn't affected now but if not operated on his condition would be very progressive) and there's no alternative to get the quality of images needed

It's just a horrible risk but if the area can be isolated to the bit the surgeon needs I'll feel much better so that's good to know...