FIGURE 1.

Amplitude and phase responses during variations of balanced SSFP (bSSFP)-type sequences. Responses are plotted as functions of the relative phase increment between consecutive RF phase from a rotating reference frame locked to the isochromat precession frequency. Traditional bSSFP (A) with high flip angle (FA), many preparation dummy scans (DS), and linear RF phase increment (PH) generates high signal amplitude with flat phase response when PH increment is an odd multiple of π. Low FA bSSFP with low DS (B) shows high signal amplitude with steep phase response for PH increments near even multiples of π. Low FA with a quadratic PH evolution (C) shows a similar response profile as low-FA bSSFP. High amplitude and steep phase response is maintained regardless of DS number with quadratic RF phase