Imaging module

Introduction

Spinach contains a very general implementation of the Fokker-Planck formalism that is able to treat 3D diffusion and hydrodynamics simultaneously with Liouville-space spin dynamics, relaxation and chemical kinetics. This is a result of our in-house research, and it is dictated by the direction in which the field is moving: many emerging magnetic resonance methods (ultrafast NMR, singlet state imaging, spatially encoded NMR, metabolite-selective MRI, catalyst MRI, hyperpolarised imaging, etc.) fall in between the established simulation frameworks: on the one hand, they require accurate simulation of three-dimensional diffusion, hydrodynamics and chemical processes; on the other, it is essential that the spin evolution in every molecule is treated quantum mechanically in a way that accurately describes spin relaxation processes. At the same time, sophisticated spatially and temporally modulated radiofrequency pulses must be accounted for. Within the Fokker-Planck formalism, things like three-dimensional diffusion, hydrodynamics and off-resonance radiofrequency appear in a very simple way – each of these is just another constant matrix to add to the background evolution Hamiltonian.