A method implemented on a magnetic resonance imaging system including an MR imaging device and a computing device, the computing device having at least one processor, at least one computer-readable storage medium, and a communication port connected to the MR imaging device, the method comprising: providing an initial flip angle schedule including initial ordered values of multiple flip angles of refocusing radio frequency pulses, each of the initial ordered values of the multiple flip angles corresponding to one of refocusing radio frequency pulses, the refocusing radio frequency pulses being configured to generate an echo train; performing an iterative process comprising, for each iteration of the iterative process, comparing the initial flip angle schedule with a first criterion, the first criterion relating to a first parameter relating to the echo train; in response to a determination that the initial flip angle schedule fails to satisfy the first criterion, adjusting the initial flip angle schedule to determine a first flip angle schedule (1006,1008), the first flip angle schedule satisfying the first criterion; comparing the first flip angle schedule with a second criterion, the second criterion relating to a second parameter relating to the echo train; in response to a determination that the first flip angle schedule fails to satisfy the second criterion, adjusting the first flip angle schedule to determine a second flip angle schedule (1012, 1014), the second flip angle schedule satisfying the second criterion; and updating the initial flip angle schedule using the second flip angle schedule; designating the first flip angle schedule as a target flip angle schedule responsive to terminating the iterative process when the first flip angle schedule satisfies the second criterion; and obtaining, based on the target flip angle schedule, a magnetic resonance signal. providing an initial flip angle schedule including initial ordered values of multiple flip angles of refocusing radio frequency pulses, each of the initial ordered values of the multiple flip angles corresponding to one of refocusing radio frequency pulses, the refocusing radio frequency pulses being configured to generate an echo train; performing an iterative process comprising, for each iteration of the iterative process, comparing the initial flip angle schedule with a first criterion, the first criterion relating to a first parameter relating to the echo train; in response to a determination that the initial flip angle schedule fails to satisfy the first criterion, adjusting the initial flip angle schedule to determine a first flip angle schedule (1006,1008), the first flip angle schedule satisfying the first criterion; comparing the first flip angle schedule with a second criterion, the second criterion relating to a second parameter relating to the echo train; in response to a determination that the first flip angle schedule fails to satisfy the second criterion, adjusting the first flip angle schedule to determine a second flip angle schedule (1012, 1014), the second flip angle schedule satisfying the second criterion; and updating the initial flip angle schedule using the second flip angle schedule; designating the first flip angle schedule as a target flip angle schedule responsive to terminating the iterative process when the first flip angle schedule satisfies the second criterion; and obtaining, based on the target flip angle schedule, a magnetic resonance signal. comparing the initial flip angle schedule with a first criterion, the first criterion relating to a first parameter relating to the echo train; in response to a determination that the initial flip angle schedule fails to satisfy the first criterion, adjusting the initial flip angle schedule to determine a first flip angle schedule (1006,1008), the first flip angle schedule satisfying the first criterion; comparing the first flip angle schedule with a second criterion, the second criterion relating to a second parameter relating to the echo train; in response to a determination that the first flip angle schedule fails to satisfy the second criterion, adjusting the first flip angle schedule to determine a second flip angle schedule (1012, 1014), the second flip angle schedule satisfying the second criterion; and updating the initial flip angle schedule using the second flip angle schedule; adjusting the first flip angle schedule to determine a second flip angle schedule (1012, 1014), the second flip angle schedule satisfying the second criterion; and updating the initial flip angle schedule using the second flip angle schedule; designating the first flip angle schedule as a target flip angle schedule responsive to terminating the iterative process when the first flip angle schedule satisfies the second criterion; and obtaining, based on the target flip angle schedule, a magnetic resonance signal.