Rotating frame revisited

This lecture revisits the concept of the rotating frame in the context of biomedical imaging, exploring the equation of motion for magnetization in different reference frames and the implications of stationary magnetization. The quantum-mechanical equivalencies in the rotating frame are also discussed, focusing on the Schrödinger representation and determining various observables. The interaction representation and higher-order perturbation theory are introduced to split the Hamiltonian into time-invariant and -dependent terms, providing insights into the dynamics of spin-1/2 systems. Special attention is given to the determination of observables like and the role of the rotating frame in quantum mechanics.