MACROMOLECULAR CONTRAST-MEDIA - A NEW APPROACH FOR CHARACTERIZING BREAST-TUMORS WITH MR-MAMMOGRAPHY

The value of macromolecular contrast agents (MMCM) for the characteriz ation of benign and malignant breast tumors will be demonstrated in th is review. Animal studies suggest a high potential of MMCM to increase the specificity of MR-mammography. The concept of tumor differentiati on is based on the pathological hyperpermeability of microvessels in m alignant tumors. MMCM show a leak into the interstitium of carcinomas, whereas they are confined to the intravascular space in benign tumors . Capabilities and limitations of the MMCM-prototype. Albumin-Gd-DTPA, for breast tumor characterization will be summarized and compared to the standard low molecular weight contrast agent Cd-DTPA. Initial expe rience with new MMCM, such as Dendrimers, Gd-DTPA-Polylysine and MS-32 5 will be outlined. The potential of ''blood-pool''-iron oxides, such as AMI-227 for the evaluation of tumor microvascular permeabilities wi ll be discussed.