Hi Melissa Jo - An MRI can help identify potential trouble spots in your breast, but only a biopsy can determine whether a lump is benign, or cancerous. So no, an MRI can't replace a biopsy. Actually, it's more likely a biopsy would replace an MRI. In any case, I'd follow your doctor's advice. And remember, 85% of lumps that are biopsied are benign, so the odds are with you. Good luck - PJH