Related Experiment Video
Updated: Sep 30, 2026

Measurement of Tumor T2* Relaxation Times after Iron Oxide Nanoparticle Administration
Published on: May 19, 2023
Theory of nonexponential NMR signal decay in liver with iron overload or superparamagnetic iron oxide particles
1Department of Radiology, New York University School of Medicine, New York, New York 10016, USA.
Abstract:
A quantitative theory is proposed for the nonexponential NMR proton signal decay observed in liver with iron overload or superparamagnetic iron oxide particles. This effect occurs for Carr-Purcell-Meiboom-Gill (CPMG) sequences and is argued to be a direct consequence of the strong magnetic field inhomogeneities generated by the iron, rather than being due to tissue compartments. An approximate mathematical form is given for the signal decay, which is fit to experimental data for samples of rat liver with iron oxide particles, for samples of marmoset liver with hemosiderosis, and for in vivo human liver with hereditary hemochromatosis. The fitting parameters obtained are consistent with the pattern of iron deposition determined from histology. For the case of hereditary hemochromatosis, a good correlation is found between a parameter characterizing the nonexponential decay and the iron concentration. Implications for practical MR quantification of hepatic iron are discussed.
Related Concept Videos
NMR Spectrometers: Resolution and Error Correction
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Magnetic Resonance Imaging
Applications Of NMR In Biology
The...
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...

