US 11,927,659 B2
Method and apparatus for frequency drift correction of magnetic resonance CEST imaging, and medium and imaging device
Yi Zhang, Hangzhou (CN); Ruibin Liu, Hangzhou (CN); Hongxi Zhang, Hangzhou (CN); and Dan Wu, Hangzhou (CN)
Assigned to ZHEJIANG UNIVERSITY, Hangzhou (CN)
Filed by ZHEJIANG UNIVERSITY, Zhejiang (CN)
Filed on Aug. 1, 2022, as Appl. No. 17/878,073.
Application 17/878,073 is a continuation of application No. PCT/CN2021/084260, filed on Mar. 31, 2021.
Claims priority of application No. 202010244399.3 (CN), filed on Mar. 31, 2020.
Prior Publication US 2022/0381866 A1, Dec. 1, 2022
Int. Cl. G01R 33/565 (2006.01); G01R 33/56 (2006.01)
CPC G01R 33/56572 (2013.01) [G01R 33/5601 (2013.01); G01R 33/5659 (2013.01); G01R 33/5605 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for frequency drift correction of magnetic resonance CEST imaging, comprising the following steps:
S1, controlling a CEST imaging system to emit a radio-frequency pulse with a flip angle less than 90° to excite a target slice;
S2, after the radio-frequency pulse is sent out, acquiring a single line of free induction decay signals and implementing step S21, or acquiring a line of non-phase encoding gradient echo signals at two different times respectively and implementing step S22;
S21, dividing the acquired free induction decay signals into odd-numbered lines and even-numbered lines, and dividing an inter-line phase difference between the odd-numbered lines and the even-numbered lines by a sampling period to obtain a value of a main magnetic field frequency drift;
S22, dividing the phase difference of the acquired two lines of non-phase encoding gradient echo signals by a signal acquisition time difference therebetween to obtain the value of the main magnetic field frequency drift;
S3, adjusting a center frequency of a magnetic resonance device in real time according to the obtained value of the main magnetic field frequency drift.