DALLAS--Magnetic resonance imaging (MRI) of the breast has recently generated much excitement as a means of improving the specificity of mam-mography and thus reducing the number of negative biopsies, Steven E. Harms, MD, of Baylor University Medical Center, said in an interview with Oncology News International.
Dr. Harms, director of magnetic resonance imaging, and his colleague at Baylor, Duane P. Flamig, PhD, director of magnetic resonance research, have developed a technique known as RODEO that further enhances MRI sensitivity, particularly in women who have a compromised mammogram.
The technique may prove especially useful in evaluating the breast for additional cancer sites in patients with a suspected solitary lesion on mammography, to determine eligibility for breast conservation (see Rodeo image ).
"We felt that the currently available commercial MRI equipment really did not provide adequate resolution or give us the confidence to call abnormal areas, so we developed a new technology based on a pulse sequence," Dr. Harms said.
RODEO (rotating delivery of excitation off-resonance) uses a combination of radiofrequency (RF) pulses, magnetic fields, computers, and a breast coil "antenna" placed over the breast, to image breast tumors as small as 3 mm. "Using RF pulses, we can excite water and selectively suppress fat or silicone or both simultaneously," he said.
When the fat signal is eliminated from the MR image, contrast-enhanced tumors appear as bright spots surrounded by dark fat. This helps physicians determine whether the mass is a tumor, cyst, hemorrhage, fat necrosis, or scar tissue. With silicone suppression, the technique can distinguish tumor masses from silicone leaks.
Dr. Harms said that RODEO may play a major role in the staging of breast cancer. He described a patient with a breast abnormality on MRI that could not be visualized with magnification mammog-raphy or sonography. "At surgery, she had disease extending exactly as shown on the MRI," he said.