NMR imaging in medicine and biology

The Nuclear Magnetic Resonance Technique (NMR) uses a particular shape of magnetic fields to see inside the human body. Sagittal, coronal and transverse cross sectionnal views are made in a given sequence without any movement of the patient. The picture obtained by NMR gives the image of the density of hydrogen nuclei (i.e. the proton) located in the water or fat molecules constituting tissues of the body and/or the relaxation times caracterising these nuclei (T1 and T2). An anatomical sight of the body can be obtained as in the CT scan but also physiological and functional description of the molecular state of the protons in the slice. It is used for ''in vivo'' spectrometry to know the amount of resonant nuclei of one specie (i.e. the nuclei of phosphorus 31) and its variation with its physiological or pathological state. The cellular pH is releable to the chemical shift of the resonant frequency peak of the nuclei. No hazardous effects are expected with this technique at fields up to 2T (IT is 10 000 Gauss) nome with rapid changes in magnetic fields of RF waves utilisation. In conclusion, NMR Imaging Technique, for now, is only used for clinical evaluation. It seems to become a useful method for medical diagnosis, as have been radiological and nuclear ones, but without any use of ionising radiations