MRI Vs Mammo (or how come results vary between the 2?)

Hi Rhiannon,

Sometimes we just need to go with the report, that the MRI is basically clean.  Whatever this new finding is, will be followed in 6 months, to determine if it's stable and and hopefully not suspicious.  I assume you'll be getting a repeat mammo at some point, as well, perhaps another ultrasound.  I was also being followed for a BIRADS 3 issue on the contralateral breast (the one without the DCIS).  After the 6 month follow-up, they determined it's stable, and they now downgraded me to BIRADS2.  I've just gotta go with it.  I realize that you have more to worry about, since you did get the ADH diagnosis on the left breast. Unfortunately, the only way we can really know what's going on is to do the bilateral mx, which many seem to be doing.  Otherwise, we have to live with the very imperfect world of imaging.  It is what it is.  My DCIS area was much, much larger than what showed on the initial mammo, resulting in three lumpectomies (eventually got wide margins), but I'm hoping that the rads took care of any stray cells.  Best of luck.

Hi Rhiannon,

I agree with CTMOM, it's good to vent, and difficult to leave these findings to "rest" for a few months.  I forgot to say (see post above) that the MRI on the non-DCIS breast was first interpreted as a BIRADS 4a by one institution, requiring biopsy, and then the second one (Memorial Sloan-Kettering) re-read and then readministered the MRI and determined that it was a BIRADS 3.  Then, they watched it for 6 months (it was a small nodule).  It hasn't changed, and they believe, based on the parameters, that it is benign, so it's now BIRADS 2.  So, the stuff on the MRI's can be very significant for some people, and false positives for others.  I am just going with what they said, and luckily I didn't go for the MRI-guided biopsy, which would have been painful (I hear that they are worse than the stereotactic core biopsies-mammo or ultrasound).  Actually, an ultrasound-guided biopsy was attempted at the first institution.  It wasn't successful (couldn't find it by ultrasound).  Sorry you have to go through this.  I think anxiety is a permanent state from now on, with all this stuff, although after awhile, it sometimes gets easier, or that's what I hear.  I lived with the ADH diagnosis for 17 years before it became DCIS, and frankly (although I had two intervening biopsies), I stopped worrying about it.  I wasn't treated as particularly "high" risk in all those years, except for a few years of 6 month follow-ups, but that stopped. 

Hi Rhiannon,

Every type of imaging has its false positives and false negatives. Mammograms can show false negatives up to 80 percent of the time and miss things as much as 20 percent of the time.

MRIs do a better job, but are much more expensive. Plus the type of MRI used also makes a difference. A 2012 study by Dr. Bruce J. Hillman etal showed that, while the false negative rate for whole body MRI has historically averaged 15%, the false negative rate for the dedicated (used only for breast imaging) Aurora RODEO MRI is less than 1%. In other words, if a RODEO MRI finds no cancer, there is only a 1% chance that it missed something, while with whole body MRI there is still a 15% chance cancer was missed.

This study also showed that while whole body MRI has been criticized for its high false positive rates, typically between 32 and 41%, RODEO MRI has a very low false positive rate of only 11%. This means if a RODEO MRI finds something suspicious, the chances of an unnecessary biopsy are much lower.

The link to this study is only for the abstract. Please PM me if you would like to see the fulltext of the study.

It sounds like you are at peace with your treatment and that is what matters most.

Sandie