Had my first MRI after CK which ended up being 5 months out. MRI was with out contrast (which I argued for contrast), showed .8mm change in size which the doctor said could be attributed to error in measurement (he didn't seem to think it had to do with swelling; maybe he should read postings on this forum) ...
Doctor also said that the telling MRI will be in six months so need to schedule one for April 2013!
Karen
Hi, Karen:
Three points:
1. I agree with you that your MRI should've included a series taken with contrast. That is the industry standard for followup MRIs after CK for an AN.
2. Your doctor is correct that the apparent change in size could be attributed to error in measurement. The inherent error for MRI is 2 mm, due to differing head positions each time you get an MRI series taken and the physical intervals apart from one another at which the images are taken. Your .8mm change easily falls within this range. Every time you have an MRI taken, the images are taken at different "slices" through the brain. If the MRI five months ago included a slice taken just beyond the edge of the tumor (where it didn't exist), the tumor would've appeared to be smaller (i.e., missing up to 2 mm of tumor tissue closer to the previous slice). Then, if one of the slices in the most recent MRI landed just inside the tumor's edge, the tumor would appear to be 2 mm larger. Any one dimension that's within 2 mm of previous measurements is statistically inconclusive. It is
very common for a static tumor to appear 1 to 2 mm bigger or smaller along one axis of measurement when comparing two MRI series. If it appears to be larger along two or three axes, however, that would be a cause for concern. From what you've related, that is not the case with your MRI. So, don't worry about the .8mm difference. It's
completely inconclusive and insignificant.
3. Your doctor is correct that the 11-month MRI will be more conclusive. That's usually the earliest MRI series in which swelling or shrinkage is likely to show up. It is standard procedure to have a followup MRI six months after the first one.
Relax, you're doing great!
Best wishes,
TW