Localization of breast lesions shown only on MRI--a review for the UK Study of MRI Screening for Breast Cancer. Advisory Group of MARIBS.

The UK study of screening for breast cancer compares mammography and dynamic contrast enhanced MRI of the breast in women at high genetic risk of developing cancer. Owing to the high sensitivity of MR in the breast, it is anticipated that some lesions will be visible only on MR. A key issue for the study is how to localize these lesions for histological verification and removal. This article reviews available methods and describes the current UK expertise and recent European developments. The use of MR compatible wires and markers has been explored in a phantom. The use of these markers in vivo is demonstrated in a case imaged by MR and mammography and further discussed. The susceptibility artefacts produced on MRI, and technical properties associated with these needles, wires and markers are discussed. The clinical pathway by which these lesions will be worked up for the study, and the quality control procedures for keeping the number of such biopsies to a minimum, are described. There is an urgent need for further centres in the UK to become proficient at removing lesions found only on MRI in support of this study and other breast MRI applications. The management of these lesions must be resolved in order to realize the full potential of MRI for screening for breast cancer in women at genetic risk, and for other diagnostic applications.