An evaluation of the contributions of diffusion and exchange in relaxation enhancement by MRI contrast agents |
| |
Authors: | Gossuin Yves Roch Alain Muller Robert N Gillis Pierre |
| |
Institution: | Biological Physics Department, University of Mons-Hainaut, Mons B-7000, Belgium. yves.gossuin@umh.ac.be |
| |
Abstract: | Magnetic compounds are known to enhance water proton relaxation, either by diffusion or by proton exchange. An experimental procedure to distinguish both mechanisms is proposed and validated by relaxation measurements made in water-methanol solutions of Dy(3+), Ni(2+), Gd(3+), Tempo, and AMI-25. The test discriminates according to the character of the transverse relaxation in water-methanol solutions: a mono-exponential decay corresponds to diffusion, while a bi-exponential decay indicates the contribution of a proton exchange. The study of ferritin and akaganeite particle solutions confirms the occurrence of a proton exchange between protons belonging to hydroxyl groups of the particle surface and free water protons. |
| |
Keywords: | Relaxation Diffusion Exchange Water– methanol solutions Ferritin Ferrihydrite Akaganeite |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|