Aims on Phosphorus-31 Magnetic Resonance Imaging

Abstract

Nuclear magnetic resonance (NMR) is capable of producing anatomical and biochemical data on the brain. Hydrogen-1 [11, 15] exists in abundance in the human body, differs in concentration from one tissue to another, and can be readily detected. Many investigators have therefore used it in tomography [8, 9, 12, 21], and the technique has reached a stage of practical application. However, since only limited biochemical data are available for ¹H, the application of ¹³C, ¹⁹F, ³¹P, and others is being tried. Using ³¹P-NMR, changes in phosphocreatine, adenosine triphosphate (ATP), sugar phosphates and inorganic phosphate can be determined, but it takes 30-60 min to produce an image. Therefore, ³¹P-NMR is inadequate for tomography at present. Thus, our aim is to obtain the local spectra of ³¹P-NMR [1, 13, 26] in vivo in a specified region, utilizing ¹H-NMR-CT (computed tomography) as guide, and to establish a biochemical diagnosis of ischemic lesions in the brain. For this purpose, we conducted a fundamental study, in which alterations in phosphorus metabolism were investigated by ³¹P-NMR spectrometry of the rat ischemic brain and the hypoxic brain, as shown in the sections “In Vitro Study” and “In Vivo Study.” In addition, we are now working on ³¹P-MRI as shown in the section headed “MRI of ³¹P”. These works will be mentioned in this order.