Magnetic resonance imaging (MRI) and spectroscopy (MRS) have contributed considerably to clinical radiology, and a variety of MR techniques have been developed to evaluate pathological processes as well as normal tissue biology at the cellular and molecular level. However, in comparison to nuclear imaging, MRI has relatively poor sensitivity for detecting true molecular changes or for detecting the presence of targeted contrast agents, though these remain under active development. In recent years higher fields (3Tesla and above) MRI systems have been developed for human studies and these provide new opportunities and technical challenges for cellular and molecular imaging. MRI is particularly rich in providing several types of intrinsic contrast that reveal different types of information on tissue composition and the physico-chemical environment within tissues. The increased signal strength at higher fields enables higher resolution images to be acquired, along with increased sensitivity to detecting subtle changes in tissues. Higher field systems also benefit the exploitation of specific contrast mechanisms such as susceptibility variations and chemical exchange effects. Here we identify 4 types of intrinsic contrast mechanisms that do not require the use of exogenous agents but which can provide molecular and cellular information and have been used in a variety of clinical or research applications. We can derive information on tissue composition by: imaging different nuclei to protons. Sodium is the only nucleus present in sufficient abundance for imaging in vivo in reasonable times, but sodium is of major interest for several applications including the evaluation of sodium stores in skin and muscle. exploiting chemical shift differences as in MRS. Imaging of fat and water represents a simple but practically important use of spectral discrimination, and more advanced methods under development promise to be able to identify different types of lipids. Proton chemical shift imaging is well established for assessments of the brain, and localized spectra of major neurotansmitters GABA and glutamate can be successfuly acquired in reasonable times. Phosphorus spectra reveal major metabolites involved in metabolism, while the use of carbon-13 agents such as glucose allow studies of e.g. the turnover of brain neurotransmitters and rate f production of glycogen. exploiting specific relaxation mechanisms that report molecular characteristics, including tissue differences in the concentrations and exchange rates of molecular species such as amides or hydroxyls using chemical exchange saturation transfer (CEST) and T1rho imaging, methods, or using quantitative magnetization transfer (qMT) and nuclear overhauser enhancement (NOE) imaging. exploiting differences in susceptibility such as detecting blood oxygenation level dependent (BOLD) effects, These efforts promise to increase the impact of molecular imaging using higher field imaging and spectroscopy. Moreover these different methods can usually be applied in the same imaging session on the same equipment to achieve simultaneous multiparametric images.