Are breast MRI's affected by breast density?

Fearless, I saw your question but I don't know the answer.  Not for sure, at least.

I don't think the effectiveness of a contrast breast MRI is affected by breast tissue density ... but I hate just offering what I think is true, and not being able to quote something or someone.   Opinions are pretty cheap on these boards.

I will look around and see what I can find, though, because it's an important question.  If it's any consolation, I have some first-hand evidence that contrast breast MRI is more sensitive than digital mammography for dense breast tissue.  My 1.8 cm tumor (IDC) was not visible at all on mammograms -- not even the one that was done an hour or so before my US-guided core biopsy.  The tumor was palpable, so everybody knew exactly where to look ... and yet, no one could see it on the mammogram images.  [Edited to add:  My PCP had referred me to a breast health center that's part of a large university-based comprehensive cancer center; so there were lots of eyeballs looking at those images.  They also do computer-aided analysis on the mammogram images.  Nada.]

OTOH, my tumor was as clear as a halogen headlight on the contrast MRI -- spiculations and all.  The MRI slightly overestimated its size ("2.0 cm"), whereas the US slightly underestimated it ("1.6 cm").  The final path showed it was right in between those numbers.

I'll look, though; and in the meantime, maybe this thread will stay active and somebody else will drop in (Beesie?  leaf?).

otter

My breasts have been labeled both very dense and very "active." My confirmation type MRI was determined to be not very helpful.  (They were checking to be sure that there was no other evidence of calcifications beyond my main group.) I was just about to get my period at the time which is not optimal due to the rampaging hormones, but they felt that it was necessary to fit it in prior to my lumpectomy. I had another digital mammogram 3-4 weeks after the surgery to make sure everything that could be seen had been seen prior to radiation. Timing of my MRI probably was part of my problem. I think that it is supposed to be a good option where density makes traditional strategies difficult.

Are breast MRIs affected by breast density?   Apparently not.

• Background:  Increased breast density increases breast cancerrisk. MRI breast is increasingly used for imaging as unlikemammography, the sensitivity of MRI breast is not affected bybreast density but rather, the amount of background enhancement.It has been suggested that increased background enhancementmay be related to the amount of proliferative breast tissuepresent; hence this may also be related to increased breastcancer risk.  Conclusion: Wefound good correlation between mammographic and MRI breast density.There was no correlation between breast density and MRI backgroundenhancement. There is a suggestion that MRI background enhancementmay be associated with a higher risk of breast cancer.   http://meeting.ascopubs.org/cgi/content/abstract/25/18_suppl/1539
• Dense breast tissue may obscure signs of malignancy on mammography and limit the evaluation of the true extent of disease. In fact, Berg et al. found the sensitivity of mammography to decrease in proportion to increases in mammographic breast density, while breast density did not affect the sensitivity of MRI.  http://www.appliedradiology.com/Issues/2010/10/Articles/AR_10-10_Argus/Clinical-indications-for-breast-MRI.aspx

Very interesting- I'm not so sure that this bodes well for me?? Can you translate "background enhancement" into layman's terms for me?

I think MRIs are not affected by breast density. "MRI", i.e. "magnetic resonance imaging," uses a powerful magnet and precisely programmed radio signals to "see" inside the body. MRI is very helpful in looking for soft tissue, such as organs, muscle, cartilage, ligaments, and tendons. MRI can identify and show the differences between healthy and unhealthy tissues. This is the reason why MRI detects more lumps other than cancerous tissues.

I have lots of scar tissue from breast surgeries.  I get MRIs every year and have never had a callback or false positive.  For me the MRI seems to be very effective at distinguishing between scar tissue and something that is of real concern.

One thing we should remember about a breast MRI is that it is nearly always done with a "contrast agent."  Gadolinium is the contrast agent that's usually used. 

I don't understand, and can't begin to explain with any sense, how a regular (non-contrast) MRI works.  It has something to do with radiofrequencies and a ginormous magnet and the way the molecules (the atoms, actually) in our body behave in the presence of all that stuff.  You're slid into a big tube, somebody pushes some buttons, there's a series of very loud and annoying noises, a computer collects the results, and ... voila!:  pictures of our innards appear on a computer screen.  It's big-time physics, for sure.

Apparently (and I really don't understand this, either), the electrons in gadolinium molecules behave weirdly in the presence of the radiofrequency waves and the magnetic field.  So, gadolinium looks very different from our water-based tissues when the images are produced on the computer screen. 

Cancerous cells tend to stimulate the growth of blood vessels, which will increase blood flow to the area and allow the tumor to grow larger.  Since the gadolinium is being injected i.v., it will be carried in the blood to places that have lots of blood vessels.  And, because of the atomic weirdness of the gadolinium, anything that accumulates gadolinium -- like those clusters of blood vessels surrounding a malignant tumor -- will appear very bright, compared to the surrounding tissue.  (Think "halogen headlight", and you'll get the idea.)

For a breast MRI, we lie on our stomach, and our boob(s) are dangled into cup-like devices called "coils" which sense the ... whatever it is ... that our tissues do in response to the radiofrequency waves and the magnet.  The pics that are produced look really goofy; but if everything works the way it's supposed to, a malignant tumor will appear as a very bright spot.  Here is an example, from "www.cdaradiology.com":

It shouldn't be difficult for a contrast breast MRI to distinguish between a malignant tumor and scar tissue, because scar tissue does not contain a lot of blood vessels.  Here's an article about breast MRI that I found on "Aboutcancer."  I regret that there is no source given on the page, but the information is interesting and relevant:

http://www.aboutcancer.com/breast_mri_textbook.htm

otter

What did the biopsy results actually say that the lump was?  I've had lots of negative biopsy results over the years; the pathology report always explained what the lump or mass was made up of and what it was called or identified to be (i.e. a mass of fatty tissue, a fibroadenoma, etc..).  You should have more information that just "negative".

hello Otter

 thank you for your post- I found it really helpful. I had 2 biopsies and 2 surgeons wanting to do a bigger better biopsy (lcis). The 3rd surgeon said- I am not sure the purpose of doing more cutting -I want  breast mri both with and with out contrast. Had test yesterday and waiting for results.Reading what you posted and link, really helped me understand the purpose of the test, and that when I get the result I will know more. So thanks for the education- I appreciate it

I don't know if I have all the facts right.  I was trying to understand what she was telling me.  She claims her onc, and her breast surgeon both agree, an  MRI for her would be useless. I think she should find some new docs, but she likes her docs, and follows docs advise to a tee, won't listen to any outside advise, but I'm just curious...  I always question things..  I tried looking up some info on it, but the only negatives I only find on mri for the breast is false positives....I'd take false positives, rather be safe then sorry.  They poo pooed my mri for 2 years, and when given the mri, guess what, cancer recurrence....in retrospect, reading my mammo reports, they saw something there, thought it was scar tissue from prior lump/ or rads.

I was just curious if anyone had ever heard of something like this before..I can't get more info other then they said something about skin thickening or density and not getting good results on breasts like  hers using mri