Preclinical Applications of Magnetic Resonance Imaging in Oncology.

The evolving possibilities of molecular imaging (MI) are fundamentally changing the way we look at cancer, with imaging paradigms now shifting away from basic morphological measures toward the longitudinal assessment of functional, metabolic, cellular, and molecular information in vivo. Recent developments of imaging methodology and probe molecules utilizing the vast number of novel animal models of human cancers have enhanced our ability to non-invasively characterize neoplastic tissue, the tumor microenvironment (TME), and follow anticancer treatments. While preclinical molecular imaging offers a wide spectrum of excellent methodologies to choose from, we will focus on magnetic resonance imaging (MRI) techniques, since they provide excellent molecular imaging capabilities and bear high potential for clinical translation. Prerequisites and consequences of using animal models as surrogates of human cancers in preclinical molecular imaging are outlined. We present physical principles, values, and limitations of MRI as a molecular imaging modality and comment on its high potential to non-invasively assess information on metabolism, hypoxia, supporting cancer tissue, and cell trafficking in preclinical cancer research.