MRI Screening
The American Cancer Society recently recommended MRI screening in
addition to mammography screening in women aged 30 and over who are
at a high risk for developing breast cancer. A recently completed
study also indicated that MRI screening of the opposite breast in
women newly diagnosed with breast cancer will find about 3% of cancers
that were missed on mammography.
No mention was made of the use of breast ultrasound as an additional
screening tool in a dense breast. Actually in experienced hands, with
a negative mammogram and a negative ultrasound there is a less than 1%
chance of missing a cancer (false negative rate). This is the same
false negative rate as a negative MRI!
The advantage of mammography and ultrasound together in dense breasts,
is that there are fewer unnecessary biopsies, it is significantly less
expensive and, I think more user friendly for the patient. Experienced
radiologists have been performing mammography and breast ultrasound a
lot longer than breast MRI and we know what we need to biopsy and what
we can safely not worry about. We have statistics accumulated over
many years to back us up.
The biggest disadvantage of screening breast ultrasound that it is
very consuming of the radiologist%u2019s time and therefore not available
everywhere, and it does not find noninvasive breast cancer (Ductal Carcinoma In Situ).
It also does not add additional information in fatty replaced breast tissue.
A lot of insurances do not reimburse for screening ultrasound.
In high risk young women with dense breasts, MRI will find a
significant number of additional cancers, but remember, so will
ultrasound. I feel strongly that screening with MRI should be
recommended with knowledge of family history, available genetic
information, the appearance of the breast on the mammogram and
pertinent medical history ( previous radiation to chest area
for example).
Most importantly breast MRI is extremely dependant on dedicated
breast coils (which most MRI centers do not have) and I think
even more importantly on meticulous attention to technique.
MRIs can look totally normal because they were not performed correctly!
As a radiologist specializing in breast imaging, my biggest
concern is that there will be a rush towards screening with
MRI in centers that are not qualified to perform it. Even
excellent radiologists will be totally fooled by a poorly
performed MRI of the breast. As of now there is no policing
of MRI centers performing breast MRIs, such as is in place for
mammography, and this will lead to huge expense, unnecessary
anxiety and biopsies, a false sense of security for the
patient and little additional accurate information.
Best regards,
Belinda Barclay-White, MD