Theory of Coherent and Incoherent Nuclear Spin-Dephasing in the Heart

TL;DR

This paper develops an analytical theory for nuclear spin dephasing in myocardial capillaries, predicting relaxation rates and potential diagnostic applications, with validation through simulations and experiments.

Contribution

It introduces a strong collision approach to model susceptibility-induced nuclear spin dephasing in myocardium, extending to other tissues and materials.

Findings

Theory accurately predicts relaxation rates and decay.

Simulation and experimental data agree with the model.

Potential diagnostic use in detecting coronary artery stenosis.

Abstract

We present an analytical theory of susceptibility induced nuclear spin dephasing in the capillary network of myocardium. Using a strong collision approach, equations are obtained for the relaxation rate of the free induction and the spin echo decay. Simulation and experimental data are well predicted by the theory. Since paramagnetic deoxyhemoglobin as the origin of nuclear spin dephasing has a higher tissue concentration in myocardium supplied by a stenotic, i. e. significantly narrowed, coronary artery, spin dephasing might serve as a diagnostic tool. Our approach can be modified for capillary networks in other tissues than myocardium and may be applied in material science.