Women who bring their magnetic resonance imaging film with them to a breast cancer centre almost always find they have to undergo the procedure again because of major technical issues.

"About 90% of the MRI scans are of no use for evaluating breast cancer," said Beryl McCormick, MD, clinical director and acting chairman, department of radiation oncology, Sloan-Kettering Cancer Center, New York, New York, United States. "Most of our radiologists won't even bother reading the film."

In presenting guidelines for MRI breast cancer examinations here at the 12^th annual National Comprehensive Cancer Network Conference (NCCN) on Clinical Practice Guidelines and Quality Cancer Care, Dr. McCormick said that breast MRI has to be performed with a dedicated breast coil.

"The procedure also has to be performed with breast image radiologists familiar with the optimal timing sequences and other technical details for image interpretation," she said in her presentation on March 16^th. "The imaging centre should have the ability to perform MRI-guided needle sampling and/or wire focalisation of MRI detected findings."

Dr. McCormick said that MRI examination can be an adjunct to other breast imaging and should "not be used in lieu of standard breast imaging with mammography and ultrasound. Breast MRI examinations should be performed and interpreted by an expert breast imaging team working in concert with the multidisciplinary treatment team."

She said there are situations where MRI is helpful in locating cancerous lesions.

"For patients with biopsy proven adenocarcinoma presenting in the axilla, a normal clinical breast exam and negative mammography, a breast MRI examination is indicated in an attempt to identify a primary cancer in the breast," she explained.

"Breast MRI may be considered for a patient with biopsy-proven breast cancer when dense breast tissue precludes an assessment for extent of disease," she added.

"Breast MRI may be useful in defining the extent of cancer, the presence of multicentric cancer in women with dense breast tissue on mammography and the extent of disease in women with locally advanced breast cancer," she said.

However, a decision on whether a woman should receive a mastectomy or breast conservation therapy should not be made solely on the basis of an MRI examination, Dr. McCormick cautioned.