Magnetic Resonance Imaging, Activatable Imaging Agents

Cobalt Ferrite Nanoparticles Fabricated via Co-precipitation in Air: Overview of Size Control and Magnetic Properties

“…As a result, it is useful for us to look at quantum spin as the superposition of the spin up and spin down states, and doing so gives us the result that the spin is actually rotating (or precessing) around the z-axis at a frequency known as the larmor frequency [71]. A classical way of looking at this is that the magnetic moments are not perfectly aligned with the z-axis, meaning that there is an angle between the z-axis and the magnetic moments, and this results in the magnetic moments feeling a torque which causes them to precess about the z-axis at a resonant frequency which is the larmor frequency [70,77].…”

“…The T 2 relaxation time, or transverse relaxation time, is the time it takes for the magnetic moments in the x-y plane to decay away, and the T 1 relaxation time is the longitudinal relaxation time and it refers to the time that it will take for the magnetic moments to return to their original longitudinal orientation (their original z-direction) [69][70]. This changing of magnetic moments can be detected by the voltage which it induces in pickup coils and based on this an image can be created [62,69,77].…”