Ferritin effect on the transverse relaxation of water: NMR microscopy at 9.4 T

Accumulation of ferritin, the iron storage protein, has been linked recently to aging and a number of pathologies. Noninvasive detection of iron storage by MRI relies on its extremely strong effect on water relaxation. The aim of this article is to characterize the effect of ferritin on transverse water relaxation in a high magnetic field, using an imaging Carr‐Purcell Meiboom‐Gill (CPMG) preparation sequence. Ferritin‐induced water relaxation showed quadratic dependence on the iron loading factor, implying a paramagnetic mechanism. However, an additional zero order term was found, that could be due to the initial stages of the iron core loading. Significant enhancement of ferritin contrast was obtained at very short τCPMG durations. This approach for enhancing ferritin contrast was demonstrated by NMR microscopy of ferritin‐injected Xenopus oocytes, thus showing the feasibility of ferritin detection in a high magnetic field, even in systems with short transverse relaxation.

[1]  M. Bronskill,et al.  Variation in measured transverse relaxation in tissue resulting from spin locking with the CPMG sequence , 1988 .

[2]  R. Ordidge,et al.  Assessment of relative brain iron concentrations using T2‐weighted and T2*‐weighted MRI at 3 Tesla , 1994, Magnetic resonance in medicine.

[3]  C. Mügge,et al.  Study of the membrane permeability of a paramagnetic metal complex on single cells by NMR microscopy. , 1993, Magnetic resonance imaging.

[4]  S. H. Koenig,et al.  Nuclear magnetic relaxation dispersion in protein solutions. II. Transferrin. , 1969, The Journal of biological chemistry.

[5]  S. Posse,et al.  Spectroscopic imaging and gradient-echo microscopy on a single cell , 1989 .

[6]  N. Dascal,et al.  The use of Xenopus oocytes for the study of ion channels. , 1987, CRC critical reviews in biochemistry.

[7]  M. M. Bradford.  A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. , 1976, Analytical biochemistry.

[8]  G. Cesareni,et al.  Mechanism of ferritin iron uptake: activity of the H-chain and deletion mapping of the ferro-oxidase site. A study of iron uptake and ferro-oxidase activity of human liver, recombinant H-chain ferritins, and of two H-chain deletion mutants. , 1988, The Journal of biological chemistry.

[9]  R. Knispel,et al.  Dispersion of proton spin-lattice relaxation in tissues☆ , 1974 .

[10]  S. H. Koenig,et al.  Transverse relaxation of solvent protons induced by magnetized spheres: Application to ferritin, erythrocytes, and magnetite , 1987, Magnetic resonance in medicine.

[11]  S Päuser,et al.  Estimation of water content and water mobility in the nucleus and cytoplasm of Xenopus laevis oocytes by NMR microscopy. , 1995, Magnetic resonance imaging.

[12]  J. Connor,et al.  Cellular distribution of transferrin, ferritin, and iron in normal and aged human brains , 1990, Journal of neuroscience research.

[13]  G. Chiro,et al.  T1 and t2 of ferritin at different field strengths: effect on mri , 1992, Magnetic resonance in medicine.

[14]  R M Henkelman,et al.  MR of human postmortem brain tissue: correlative study between T2 and assays of iron and ferritin in Parkinson and Huntington disease. , 1993, AJNR. American journal of neuroradiology.

[15]  J. Bulte,et al.  Comparison of t2 relaxation in blood, brain, and ferritin , 1995, Journal of magnetic resonance imaging : JMRI.

[16]  C. Morris,et al.  Brain iron homeostasis. , 1992, Journal of inorganic biochemistry.

[17]  Stephen J. Blackband,et al.  Nuclear magnetic resonance imaging of a single cell , 1986, Nature.

[18]  S. H. Koenig,et al.  Relaxometry of ferritin solutions and the influence of the Fe3+ core ions , 1986, Magnetic resonance in medicine.