Numerous and diverse
contrast agents are available in MRI. Their use is focused on two directions : microcirculation imaging and cell capture imaging. Microcirculation imaging uses
gadolinium chelates and technical advances in MRI. It quantifies perfusion and capillary permeability applying a physiological analysis to the tissue enhancement curve. Cellular imaging uses labeled cells as
contrast agents ; the cells can be labeled in vitro or in vivo. The roles of imaging in
cancer are numerous. For diagnosis, detection is improved, particularly for liver
metastases with the development of cellular imaging and liver-specific
contrast agents. Cellular imaging opens promising perspectives for cellular
therapy. Microcirculation imaging characterizes
tumors more specifically, particularly in breast imaging. Regarding treatment follow-up, the impact of imaging is considerable. Microcirculation imaging predicts treatment response even before initiation of
therapy. During treatment, it allows a more complete evaluation taking into account physiological parameters, better adapted to monitor
therapies currently in development, such as
anti-angiogenic drugs.
Therapeutic effects can be detected earlier, before morphological changes. Cellular imaging offers new prospects to monitor cellular
therapy. The use of MRI
contrast agents is moving towards the coupling of functional to morphological analysis. This constitutes a new approach perfectly adapted to diagnosis and
therapy follow-up in oncology.