Christina Applegate's breast cancer diagnosis was a wakeup call for many women.

When we heard that Christina Applegate was diagnosed with breast cancer, we were shocked. After all, the Samantha Who? star is only 36.  Her representative said, "Christina Applegate was diagnosed with an early form of breast cancer. Benefiting from early detection through a doctor-ordered MRI, the cancer is not life-threatening. Christina is following the recommended treatment of her doctors and will have a full recovery."

Our first thought: What's a doctor-ordered MRI? And should we be requesting one from our own doctors? We called friend of momlogic OB/GYN Suzanne Gilberg-Lenz for her perspective.

momlogic: What's the difference between a mammogram and breast MRI?

Dr. Suzanne Gilberg-Lenz: A breast MRI is an image produced by a magnet, and can show finer detail when 'thin cuts' of the image are made. A mammogram is more like an X-ray and the image's quality is not as detailed.

momlogic: Should I request a breast MRI?

Dr. Suzanne Gilberg-Lenz: A breast MRI has been shown to be superior in women with a family history of breast cancer, women who carry the breast cancer gene, or people who have had breast cancer in the past. It is not typically offered to women who don't meet that criteria. The data does not support widespread use yet as a screening tool. However, it is very important for diagnostic use, especially in someone who's already had a mammogram that came back positive for cancer."

momlogic: Are there any downsides to breast MRIs?

Dr. Suzanne Gilberg-Lenz: It's been reported that breast MRIs produce more false positives, which is why they are not generally used in otherwise low-risk women. But when they are used judiciously, they are a wonderful screening tool.

Have you ever had a breast MRI? Share your story below.