new 4-minute breast mri is just as accurate as longer scans
For nearly a decade, magnetic resonance imaging (MRI) of the breast has been acknowledged by experts as more thorough and accurate than conventional mammograms. More importantly, breast MRI can identify women at risk of breast cancer (BCa) because it has 98% sensitivity for detecting cancers that are likely to progress to highly lethal forms of the disease. Compare that with only 52% sensitivity of mammograms for the same condition.1
Until recently, the length of time needed for a full breast scan using a multiparametric MRI protocol was just under thirty minutes. The time-consuming scan, coupled with the cost of tying up a magnet for a half hour per patient, was seen as a downside of breast MRI. Thus, MRI was seen as a modality that would be reserved for certain cases such as women with dense breast tissue or women at high risk for BCa. Then, about three years ago, a simplified protocol that streamlined imaging to 21 minutes was shown to be as effective at diagnosing BCa in dense breast tissue as the longer protocol. However, even 21 minutes was rejected as a screening modality such as mammography is.
Shorter Time for Breast MRI Just as Powerful
Now, a highly abbreviated (4 minute) breast MRI protocol has demonstrated usefulness for dense-breast evaluations in high-risk patients. A recent paper delivered at the 2016 European Congress of Radiology (ECR) in Vienna reported that the 4-minute protocol was just as effective in detecting BCa in high-risk patients with dense tissue as longer protocols. The 100 women in the study previously had inconclusive mammograms and negative clinical examinations (no lumps could be felt). The abbreviated protocol was nearly identically sensitive as the long protocol. “The sensitivity and negative predictive value (NPV) with the abbreviated breast MRI protocol in identifying malignant lesions were 100%, with a high specificity of 97.78%. All 10 malignant lesions were identified — invasive and in situ. Four out of four invasive malignant lesions with a diameter 1 cm or smaller were identified.”2
While more research is called for with larger patient populations, this study is good news for at-risk women. Mammography is not only a flawed technology in terms of false positives and false negatives, it also exposes women to a small amount of ionizing radiation – the kind that is associated with causing cancer. The Breast Cancer Fund cautions, “There is considerable evidence that medical X-rays, which include mammography, fluoroscopy and computed tomography (CT) scans are an important and controllable cause of breast cancer.”3
The 4-minute MRI protocol is significantly more cost effective without sacrificing diagnostic accuracy. MRI of the breast picks up tissue distortions and changes that are characteristic of cancers, even slow-growing ones. By greatly reducing the time and associated costs, and eliminating exposure to radiation, more women will ultimately have access to a safer and superior imaging technology.
1Brosky, John. “Breast MRI remains underused, claims German pioneer.” Women’s Imaging News Apr. 4, 2011. http://www.auntminnieeurope.com/index.aspx?sec=sup&sub=wom&pag=dis&ItemID=604985
2 Yee, Kate Madden. “Simplified protocol improves breast MRI screening.” Women’s Imaging News Mar. 3, 2016. http://www.auntminnieeurope.com/index.aspx?sec=sup&sub=wom&pag=dis&ItemID=608687