Breast imaging technology: Application of magnetic resonance imaging to angiogenesis in breast cancer

The present review describes the use of MRI to evaluate neoangiogenesis in breast tumours noninvasively. MRI is now widely used to provide anatomical cross-sectional images, with excellent definition of soft-tissue morphology. For many applications, the technique has supplanted computed tomography, particularly for imaging of the central nervous system. Unlike conventional X-ray imaging or computed tomography, which produce images that show the X-ray attenuation of tissues, MRI measures the amount of hydrogenous materials (water and lipid) in tissues. The technique allows the appearance of images to be modulated, allowing a range of different images to be obtained from any given set of tissues. This ability to select and manipulate the contrast between different tissues, as well as to obtain image sections at any orientation, has led to a rapidly growing range of clinical applications.In imaging breast cancer, MRI is increasingly being used in clinical problem solving, in situations in which X-ray mammography is equivocal (due for example to dense breast parenchyma, surgery or breast implants) and ultrasound is not informative. Many of the clinical applications to date pertain to morphological evaluation, often based on the use of contrast agents, which highlight areas with increased vascular permeability. Such high-resolution images enable sections through the breast to be observed, typically providing full three-dimensional image sets of both breasts, allowing identification of multifocal and contralateral disease. Such images allow cancer to be detected with high sensitivity, but may not distinguish some benign conditions, particularly fibroadenoma, from malignant disease.More sophisticated MRI methods have recently been developed that provide additional, functional information about tumours. By observing the uptake and washout of MRI contrast agents, malignant and benign disease can be better discriminated. Using methods that involve measurement of the transit o