[Chemical exchange saturation transfer (CEST) : Magnetic resonance imaging in diagnostic oncology].

BACKGROUND: Contrast generation by chemical exchange saturation transfer (CEST) is a recently emerging magnetic resonance imaging (MRI) research field with high clinical potential.
METHODS: This review covers the methodological principles and summarizes the clinical experience of CEST imaging studies in diagnostic oncology performed to date. RESULTS AND
CONCLUSION: CEST enables the detection of lowly concentrated metabolites, such as peptides and glucose, through selective saturation of metabolite-bound protons and subsequent magnetization transfer to free water. This technology yields additional information about metabolic activity and the tissue microenvironment without the need for conventional contrast agents or radioactive tracers. Various studies, mainly conducted in patients with neuro-oncolgic diseases, suggest that this technology may aid to assess tumor malignancy as well as therapeutic response prior to and in the first follow-up after intervention. KEY POINTS: CEST-MRI enables the indirect detection of metabolites without radioactive tracers or contrast agents. Clinical experience exists especially in the setting of neuro-oncologic imaging. In oncologic imaging, CEST-MRI may improve assessment of prognosis and therapy response.