New OHSU Research Demonstrates How MRI Can Detect Cancerous Breast Tumors
11/03/08 Portland, Ore.
Latest results demonstrate that “shutter-speed” computer analysis distinguished malignant from benign tumors 100 percent of the time
Oregon Health & Science University researchers are playing the leading role in developing a new breast cancer screening method that will likely reduce or eliminate unnecessary biopsy surgeries. Their findings are published in the current issue of the Proceedings of the National Academy of Sciences.
The research effort, led by Charles Springer, Ph.D., uses a Magnetic Resonance Imaging (MRI) technique and the researchers’ newly developed software – called the “shutter-speed” model ‑ to analyze image data of breast cancer patients. Springer and colleagues aim to develop a new, minimally invasive, yet precisely accurate, approach to determining whether tumors located in the breast are malignant or benign. Other OHSU researchers contributing to the project are: Wei Huang, Ph.D., Xin Li, Ph.D., Alina Tudorica, Ph.D., Ian Tagge, B.S., William Rooney, Ph.D., and Jingang Xu, M.S.
“While standard mammography is effective, it also results in a very significant number of false-positive results,” explained Springer, director of the OHSU Advanced Imaging Research Center, afacility dedicated to MRI-based research and to expanding the clinical uses of MR science. Springer also is a professor of physiology and pharmacology, and biomedical engineering, and a member of the OHSU Knight Cancer Institute.
“This means that following a positive mammographic indication, a large number of women are referred to undergo the physical and mental stress of a biopsy procedure only to learn that they in fact do not have breast cancer. We believe that an MRI examination aided by our shutter-speed model analysis will provide a much clearer diagnosis and will become the intermediate step between a mammographic scan and a biopsy intervention if breast cancer is suspected from both the mammogram and the MRI results. Adding this intermediate diagnostic step would greatly reduce the number of biopsy surgeries and also reduce the pain, stress and expense for most patients.”
Currently, a different form of MRI data analysis called the “standard model” by the OHSU researchers, is used occasionally for characterizing lesions in the breast. However, this older system offers little improvement over mammography when attempting to distinguish between malignant and benign tumors.
To test their newer analytical model, Springer and colleagues employed their shutter-speed technique to analyze MR images of 22 women volunteers who had previously screened positive for breast cancer by mammography and/or clinical examination. The shutter-speed software operates by using a complex mathematical formula to track the passage of injected contrast dye through a tumor area. Contrast dyes are commonly used in medical imaging to increase the visibility of tissue abnormalities.
When viewed through the shutter-speed analysis, the MRI data suggested that only seven of the 22 women actually had malignant tumors. These projections were later shown to be 100 percent accurate after each of the study participants underwent subsequent biopsies for pathology determinations.
“Typically, 75 percent of mammographically-indicated biopsies yield negative pathology results, meaning that an intermediate step such as an MRI determination could greatly reduce the number of unnecessary biopsy surgeries,” added Springer.
A second paper published in same issue of the Proceedings of the National Academy of Sciences provides increased detail and physicochemical principles underlying the shutter-speed model and the data analyzed by this software, which allows malignant tumors to be so well distinguished from benign tumors. The new model correctly accounts for the speed of water molecule interchange between tissue compartments.
Other collaborators on this research are Elizabeth Morris, M.D., and Ya Wang, M.S., at Memorial Sloan Kettering Cancer Center; and Venkatraman Seshan, Ph.D., at Columbia University. This work began some years ago, when Springer, Huang, Li, Tudorica, and Rooney were at Stony Brook University (and Brookhaven National Laboratory), both on Long Island. Before coming to OHSU, Huang moved to MSKCC and Weill Cornell Medical College, with Columbia in Manhattan.
Oregon Health & Science University is the state’s only health and research university, and Oregon’s only academic health center. OHSU is Portland's largest employer and the fourth largest in Oregon (excluding government), with 12,700 employees. OHSU's size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves patients from every corner of the state, and is a conduit for learning for more than 3,400 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to every county in the state.