News about MRI effectiveness for DCIS

My DCIS was detected in one breast via regular screening mammogram 2 months ago. Magnification mammo, stereotactic biopsy, and MRI with contrast of both breasts to make sure nothing was missed all followed in quick succession. I chose BMX because DCIS was small but an agressive type and I wanted to try to avoid radiation & chemo. Also didn't  want to have to keep worrying it would show up on other side. My surgeon said all breast tissue from back of underarms, down to second rib and up to clavicle would be taken as well as the fascia on all the muscles. He said it was difficult to get it all, but felt chances of reoccurance would be 1-2%. Surgery was 4 weeks ago and I got the pathology report last week. DCIS was indeed small and no more cancer found in that breast tissue, nodes, or fascia. LCIS was found in what we thought was "good" breast - same agressive type. How could this have been missed! Fortunately the report shows they got it all, nodes clear, fascia clear. I will not have to have radiation or chemo.

What if I had gone with conventional wisdom and left the "uninvolved" breast alone? I would have had a regular mammo next year and by then it might have been too late.