It's common for women to have magnetic resonance imaging-- an MRI-- if a mammogram shows something suspicious in a breast. But on a machine at Dartmouth-Hitchcock Medical Center, some women are getting two tests in one.
"We're adding on something that's really pretty easy to add right into the exam. We do it simultaneously so it doesn't really add time. There can be some cost because of instrumentation, but it would fit right into what we call the clinical workflow pretty easy," said Keith Paulsen of the Thayer School of Engineering at Dartmouth.
What's different here are the eight cables that Paulsen and other Dartmouth engineers have added to the MRI table, while reworking the design so that more tissue is visible to doctors. The cables are part of an exam technology called near-infrared spectroscopy. They transmit light from laser sources during the MRI. Doctors here believe Dartmouth is the only site in the country testing the combined approach.
While the MRI provides precise images of questionable lesions, the near-infrared actually shows what the lesion or tumor is doing-- how it's functioning with water, blood and fats.
"So a little of the downfall of MRI is that it has such a high sensitivity for all kinds of abnormalities in the breast that we are often biopsying things that tend to be benign. So if we can find some other modality, or exam, that will help us fine tune that a little more-- and say, you know, even though this looks like a breast cancer, it's not behaving like a breast cancer in terms of its profile when it interacts with light. That would help us be more specific about what lesions we really are concerned about and need to biopsy, and the ones we think we can leave alone," said Dr. Roberta DiFlorio-Alexander, a Dartmouth radiologist.
DiFlorio-Alexander says 80 percent of women who are biopsied after MRI are negative or false positive for breast cancer. Their study, that used the combined approach on women already diagnosed with breast cancer, dropped that to 67 percent.
"We'd love to drop that even further because of the anxiety that it generates, because of the cost-- a lot of different issues," DiFlorio-Alexander said.
She says there's still a long way to go and more study is needed, but they're optimistic that one day the technology will be used to improve MRI's ability to distinguish cancer from benign abnormalities.
Dartmouth's study on this new approach to breast imaging is being published in the February edition of the journal Academic Radiology.
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