1. A system that helps to track the position of the irradiated target volume, including: a magnetic resonance (MR) scanner； a linear accelerator device (LINAC)； and a processor configured to execute computer-executable instructions stored in the memory, the instructions comprising: identifying the position of the linear accelerator (LINAC) radiation source source around the target volume； identifying the visualization volume of interest, defined on one side by a plane perpendicular to the radiation beam emitted by the LINAC source, moreover, the volume of interest contains the target volume and at least one risk organ (OAR)； the purpose of the first direction of phase coding, parallel plane； a second assignment phase encoding direction parallel to the plane, wherein the second phase-encoding direction perpendicular to the first phase encoding direction； the purpose of the reading direction, which is parallel to the radiation beam； visualization of the visualization volume of interest and the target volume, which includes phase coding in the first and second directions and frequency coding in the reading direction； determining the position of the target volume relative to the radiation beam； and controlling a collimator between the LINAC source and the visualization volume of interest to keep the radiation beam at the target volume and remote from the OAR based on the determined position of the target volume. 2. The system of claim 1, wherein the instructions further comprise: collecting less than all central points of k-space data when visualizing the volume of interest. 3. The system of claim 1, wherein the instructions1. Система, которая способствует отслеживанию положения облучаемого целевого объема, включающая в себя:магнитно-резонансный (MR) сканер；устройство линейного ускорителя (LINAC)； ипроцессор, выполненный с возможностью исполнения машиноисполняемых инструкций, хранящихся в памяти, причем инструкции содержат:идентификацию положения источника пучка излучен
