Breast MR imaging aids high-risk women

January 22, 2008

Once again, MRI has outrun other modalities as a supplemental tool for screening high-risk women.

A large prospective screening trial from the University of Pennsylvania compared screen-film mammography, digital mammography, whole-breast ultrasound, and contrast-enhanced MRI in a population of 569 asymptomatic women. In this single-center trial, funded by the National Cancer Institute, the definition of high risk included women with a 25% lifetime risk based on genetic testing or Gail or Claus models and those with a history of cancer in the contralateral breast.

Of 95 lesions recommended for biopsy, 11 were malignant (11.6%). Seven of the 11 cancers were seen on only one modality: one with digital mammography and six with MRI alone. No cases were seen on either screen-film mammography or ultrasound alone.

"In our study, MRI detected the highest percentage of clinically occult breast cancers in a high-risk population, more than digital mammography, ultrasound, and screen-film mammography," said RSNA meeting presenter Dr. Lily Kernagis, a fellow in women's imaging at Penn.

Follow-up was carried out for one to three years and revealed no new breast cancer diagnoses. Based on the results and follow-up, multimodality screening had a negative predictive value of 100%, sensitivity of 100%, and specificity of 84.9%.