Library · Test
Breast MRI
Make it clearer
Breast MRI is a test that uses a very powerful magnet to see inside the breast; 1.5 tesla magnets are widely used in breast imaging. It does not replace mammography or ultrasound: it is used alongside them when more information is needed.
An intravenous contrast agent, usually gadolinium, almost always has to be injected, and that is what makes this test different. The shape of the tumor is not the only thing that matters; what matters is the enhancement kinetics, that is, how the tumor fills with contrast over the first few minutes and how it washes that contrast out. The scanner takes images one after another, and that is how contrast movement becomes visible.
Most malignant lesions have a lot of blood vessels, so contrast floods into them quickly and leaves just as fast. That pattern of a quick rise and fall is one of the things the radiologist looks for.
In women at high risk of breast cancer who have no symptoms, this test finds more cancers than mammography, ultrasound, or the two combined. Even so, it is not the first choice for everyone: it costs more, it takes longer, it requires a contrast injection, and sometimes it flags something as suspicious that turns out to be nothing.
In brief
Breast MRI complements mammography and ultrasound; 1.5 tesla magnets are widely used.
It almost always requires intravenous gadolinium contrast, and it measures tumor shape and enhancement kinetics.
You are not looking at a still photo, but at how contrast flows in and out.
Most malignant lesions take up and wash out contrast quickly because they are highly vascular.
In high-risk women without symptoms it finds more cancers than mammography and ultrasound combined, but it costs more, takes longer and yields false positives.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingBreast MRI in Clinical Practice, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated