Overview of Breast Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) has proven to be a powerful tool in examining the breast. It works alongside mammography and ultrasonography as a method for diagnosing breast conditions. The main purpose of a breast MRI is to analyze and better understand any signs of cancer.
Research has shown that a breast MRI is capable of detecting breast cancer more effectively than either mammography, ultrasonography, or combining these two methods, especially in women who are asymptomatic but at high risk of developing breast cancer. The main goal of this screening process is to spot breast cancer when it’s small and hasn’t spread to the lymph nodes, which can significantly decrease the chances of dying from the disease.
This article will delve into the reasons for carrying out a breast MRI for both screening and diagnosis. It will also provide insights about how the MRI process is performed and explain some common discrepancies that may occur in the images.
Why do People Need Breast Magnetic Resonance Imaging
One of the main reasons to get an MRI of the breast is to check for breast cancer. Research has shown that an MRI can detect breast cancer more effectively than a mammogram or ultrasound alone.
Women who are at high-risk for breast cancer should have an MRI of the breast every year. This includes:
- Women with a 20% or higher chance of developing breast cancer in their lifetime.
- Women who carry the BRCA gene mutation or have a close family member with the mutation who hasn’t been tested.
- Women who have had radiation therapy on their chest between the ages of 10 and 30.
- Women with specific genetic syndromes that increase the risk of breast cancer.
For those who have already been diagnosed with breast cancer, an MRI is essential for several reasons, including:
- Checking the size and location of the cancer before surgery.
- Testing the other breast in cases where there’s a high chance of cancer in both breasts, such as with lobular carcinoma.
- Staging the cancer to plan treatment.
- Monitoring how the tumor responds to treatments like chemotherapy or hormone therapy.
Aside from cancer, there are other situations where a breast MRI might be necessary, such as:
- Women with dense breast tissue, which can increase the risk of breast cancer.
- Differentiating between a scar and cancer recurrence.
- Women suspected of having inflammatory breast cancer, a type of cancer that causes the skin to become red and swollen.
- Investigating enlarged lymph nodes in the armpit when mammography and ultrasound fail to identify a breast tumor.
- Checking for any problems with silicone breast implants.
- Looking into the cause of nipple discharge when previous images haven’t provided clear results.
A survey showed that specialists tend to order more breast MRIs than primary care providers (PCPs). The reasons they give are usually associated with evaluating clinical findings with negative mammograms and ultrasounds, evaluating a new breast cancer diagnosis, staging cancer, and monitoring the response to chemotherapy.
However, using MRI for breast imaging can present challenges. These include high costs, limited availability in some medical centers, extended examination time, the need for an IV contrast medium (a substance that helps make tissues more visible), and the risk of false positive results, which could lead to unnecessary tests or treatments.
How is Breast Magnetic Resonance Imaging performed
When we’re looking at the structure of your breast tissue, we can use a machine with a powerful magnetic field, named a 1.5 Tesla magnet. You’ll lie face-down, and a special piece of equipment, made specifically for imaging breasts, will capture detailed pictures of your breast tissue. The doctor may need to inject a contrast medium, a safe dye, into your veins to help clearly highlight certain areas. The only time you wouldn’t receive this dye is during the checks of silicone implants.
The timing of these images is important, especially for women. It’s usually best to do it between days 7 and 14 of your menstrual cycle because this timing reduces the natural impact your hormones can have on the results and it also decreases the chance of mistaking normal changes for disease (false positives).
The images that the magnet produces are based on the interaction of protons inside the tissue. It’s easier to see cancerous cells because they look different from normal breast tissue. The magnet tracks these differences and shows them on images. It’s also important to suppress “noise” or distracting elements in the images – things like fat can make it difficult to read them and spot subtle changes.
Predominantly, we use this technique to spot breast cancer. By enhancing the images with the contrast dye, we can distinguish between harmless and harmful growths in your breast. Pictures taken after the dye is given help doctors to examine both the form of any tumours and how they behave when the dye is present. Some benign lesions can appear similar to malignant ones, and vice versa. So along with these patterns, the physical characteristics of the lesion are also considered to confirm its benign or malign nature.
There are a few other kinds of imaging studies we can use too, and they are designed to cut down both the duration and cost of the screenings. They are being investigated currently, and are expected to enhance the accuracy and specificity of breast MRIs.
However, we need to keep an eye out for “artifacts” – these are things that can cause mistakes in the images. They can come about due to multiple reasons, including the patient not staying still, metallic objects causing field distortion, or improper positioning during the scans. These issues can be resolved with some practical steps like advising the patient to remain immobile, removing all metallic pieces from the patient, and ensuring proper positioning.
There can also be technical issues with the procedure, such as interference from external radio signals, signals from tissues outside the field-of-view overlaying on the main image, and differences in the frequency of protons in water and fat. The majority of these issues can be fixed by adding certain checks to the procedure like quality control of the imaging unit, increasing the field-of-view, or using proper scanning techniques.
What Else Should I Know About Breast Magnetic Resonance Imaging?
Knowing the significance of an MRI for the breast and when it should be used for screening and diagnosis helps catch health issues faster, manage them more effectively, and improve the patient’s overall health outcome. Recognizing potential flaws in the technique and finding ways around them ensures high-quality images and helps cut out unnecessary treatments.
