Hi Scorpiowoman
Like you I had several different types of imaging including mammogram, tammography, ultrasound and now have MRI every 6 weeks as I'm having neoadjuvant chemo at the moment. My doctors have found that the MRI definitely is giving them the best information and infact has picked up some small DCIS that other imaging did not find ( I have IDC). If you are premenopausal I have been told that the MRI is most accurate during days 7 to 10 of your cycle as that is when the tissue is less dense and they can see things easier.
Good luck with your tests. I hope you get happy results.
Take care
Pollyrose