I am reading a text about how MRI works and I came across a thing that I am totally confused. The book mentions about that few particles side by side with their nuclei spinning at the same frequency but they all have a phase difference. Since MRI cannot measure the phase differences directly, it will try to encode the phase differences in term of so called pseudo-frequency. With each unique pseudo frequency the MRI will know where that particle coming from. The thing I am confused is how can each nuclei share a common frequency yet they have a different frequency due to their phase differences? Am I misunderstanding something????