Antonio Luna, MD, Editor

Imaging is used for the “in vivo” phenotyping of this diversity of cancer. In this setting, functional and molecular information from imaging techniques, classically provided by nuclear medicine, and specifically PET, has been considered essential to understand the insights of cancer and its microenvironment, and the changes induced with therapy. MR imaging has emerged with the potential to represent different tumor characteristics using a multiparametric protocol. Combining morphologic and functional sequences, MR imaging is able to inform different tumor hallmarks, such as cellularity, microstructure, metabolism, angiogenesis, and hypoxia. All of this quantitative information helps to perform precision diagnostics, which can create impact as tailored treatment to the individual patient. Now, the radiologist must integrate these numeric biomarkers in our classical descriptive reports and learn how to transmit them to clinicians, and to become a central part of multidisciplinary oncologic teams. In addition, research in collaboration with informatics, biotechnologists, and engineers is needed to expand its clinical role. Hence, all of these steps are necessary for radiologists to advance in the goal of improving the personalized care of oncologic patients in this new molecular era as functional imaging information, specifically MR imaging, can create a paradigm shift in the diagnosis and therapy of different tumors.

Thanks to an enthusiastic group of researchers, this issue resumes the role of MR imaging in modern oncology, revealing its potential role in personalized medicine and clinical trials of oncologic drugs. A succinct technical overview of the most “popular” functional sequences, such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MR imaging, and molecular one (meaning sequence), such as MR spectroscopy, are also performed. In addition, novel MR imaging probes, such as chemical exchange saturation transfer MR imaging, hyperpolarized MR imaging, blood-oxygen–dependent level, MR elastography, specific contrast, such as hepatobiliary contrast agents, superparamagnetic particles of iron oxide, or activatable nanoparticles, are also reviewed. A deeper understanding of the clinical use of all of these techniques can be obtained in the specific articles that deal with the applications of functional and molecular MR imaging in the detection, characterization, and therapy monitoring of malignancies in the brain and the body.