MRIs play an important role in the diagnosis of cancer and the planning of treatment because they are very proficient at distinguishing between normal, healthy tissue and cancerous cells. Because they are precise instruments, they are one of the most effective tools for identifying the disease early.

The sensitivities of MRI, mammography, and sonography in the detection of malignancy were 100%, 81.8%, and 86.4%, and the specificities were 93.9%, 99%, and 98.1%. The specificity of MRI increased from 92.8% to 94.5% over the course of the study (2006–2007).

A new study shows follow-up MRI can detect curable early breast cancers that cannot be found by mammography or physical exam.

When is breast MRI used? To help determine the extent of breast cancer: Breast MRI is sometimes used in women who already have been diagnosed with breast cancer, to help measure the size of the cancer, look for other tumors in the breast, and to check for tumors in the opposite breast.

MRI is much more sensitive than mammography. It can find invasive breast cancers sooner than mammograms, and it can rule out abnormalities that appear suspicious on a mammogram. Unfortunately, MRI is much too expensive for routine screening.”

CT, PET, and bone scans can be helpful tools in the right situations, such as for people whose symptoms, physical examination findings, size of the breast tumor or lymph nodes, or blood test results suggest later-stage breast cancer (stages III and IV).

Results. The radiologist may discuss the results of the MRI with you right after the test. Complete results are usually available to your doctor in 1 to 2 days. An MRI scan can sometimes find a problem in a breast, even when the size and shape of the breast looks normal.

A breast MRI is used to assess the extent of breast cancer. It’s also used to screen for breast cancer in women thought to have a high risk of the disease. Your health care provider may recommend a breast MRI if: You’ve been diagnosed with breast cancer and your provider wants to determine the extent of the cancer.

“The ideal time for MRI of the breast is approximately between day five and 15 of the menstrual cycle,[5] because the luteal phase of the menstrual cycle with the associated increase in estrogen and progesterone leads to the stroma being edematous with development of the lobules.

Still, breast MRI is not perfect. Research has shown that breast MRI results in more false positives than mammography. A false positive is when a test finds something that initially looks suspicious but turns out not to be cancer.

MRI is very good at finding and pinpointing some cancers. An MRI with contrast dye is the best way to see brain and spinal cord tumors. Using MRI, doctors can sometimes tell if a tumor is or isn’t cancer.

MRI breast scanning is the most sensitive imaging modality available, detecting suspicious lesions or breast cancer at the earliest possible stage of development with a 70-90 percent accuracy rate.

Breast MRI is typically performed as a supporting evaluation to mammography, ultrasound and breast biopsy. Some of the reasons to perform a breast MRI include: to assess multiple tumor locations, especially prior to breast conservation surgery.

The x-ray images often make it possible to detect tumors that cannot be felt. Screening mammograms can also find microcalcifications (tiny deposits of calcium) that sometimes indicate the presence of breast cancer. Mammograms can also be used to check for breast cancer after a lump or other sign or symptom of the disease has been found.