Systems and methods for magnetic resonance imaging

A system for magnetic resonance imaging (MRI)-guided radiotherapy, comprising:

• at least one storage device including a set of instructions;
• and
• at least one processor configured to communicate with the at least one storage device, wherein when executing the set of instructions, the at least one processor is configured to direct the system to perform operations including:
• obtaining first auxiliary signals and second auxiliary signals collected by an MRI device during an MRI scan of a target subject, wherein the first auxiliary signals are collected by the MRI device at a first time before radiotherapy rays are emitted, and the second auxiliary signals are collected by the MRI device at a second time after the radiotherapy rays are emitted;
• determining, based on the first auxiliary signals and the second auxiliary signals, whether a first motion amplitude of the target subject from the first time to the second time is greater than a threshold;
• and
• determining, based on a determination result of whether the first motion amplitude is greater than the threshold, whether to stop emitting the radiotherapy rays.

A non-transitory computer readable medium, comprising at least one set of instructions for magnetic resonance imaging (MRI)-guided radiotherapy, wherein when executed by one or more processors of a computing device, the at least one set of instructions causes the computing device to perform a method, the method comprising:

• obtaining first auxiliary signals and second auxiliary signals collected by an MRI device during an MRI scan of a target subject, wherein the first auxiliary signals are collected by the MRI device at a first time before radiotherapy rays are emitted, and the second auxiliary signals are collected by the MRI device at a second time after the radiotherapy rays are emitted;
• determining, based on the first auxiliary signals and the second auxiliary signals, whether a first motion amplitude of the target subject from the first time to the second time is greater than a threshold;
• and
• determining, based on a determination result of whether the first motion amplitude is greater than the threshold, whether to stop emitting the radiotherapy rays.