Tissue characterization is a major and ultimate goal of imaging, whether morphological (Computed Tomography, Magnetic Resonance Imaging) or metabolic (PET-FDG-[18F]). Functional imaging, using the MRI, began several years ago with the perfusion of lung nodules and very recently with diffusion-weighted imaging applied to the lung cancer. The authors review the interest and the place of diffusion-weighted and perfusion MR imaging in the diagnosis, early staging and follow-up of patients with lung cancer.