ABSTRACT
This chapter introduces the general basics of X-nuclei Magnetic Resonance Imaging (MRI). Standard MRI is based on the detection of the nucleus (the proton) of the hydrogen atoms in the body from water molecules and other metabolites. The main biological targets of X-nuclei MRI methods are the cellular energy metabolism and ion/metabolite homeostasis, which are related to both the production and consumption of energy in the body (and will be described in more details in the following sections). Many trace elements also play important metabolic roles in the body, while some others have no known function or appear to be toxic. Iron is a component of hemoglobin used to transport oxygen to cells. Glucose is generally the main source of energy in cellular respiration, which starts with glycolysis. However, other nutrients such as more complex carbohydrates, fats and proteins can also participate to this metabolic pathway, by either being broken down into glucose molecules to enter the process.
