title: Simultaneous dynamic R2R2', and R2* measurement using periodic π pulse shifting multiecho asymmetric spin echo sequence moving estimation strategy: A feasibility study for lower extremity muscle.
abstract: The purpose of this study was to demonstrate the feasibility of simultaneous dynamic R2, R2', and R2* measurement of lower extremity muscle by means of a new method in which the periodic π pulse shifting multiecho asymmetric spin echo (psMASE) sequence is adopted together with a moving estimation (ME) strategy.
  
  
  
  The psMASE sequence is a modification of the multiecho asymmetric spin echo sequence determined by shifting the 180 ° refocusing pulse periodically. ME strategy is introduced to improve the temporal resolution of the simultaneous dynamic measurement of R2, R2', and R2*. Reproducibility measurements and comparison with reference methods were conducted. Furthermore, this method was tested on 10 healthy volunteers with the dynamic imaging of lower extremity muscles during a cuff occlusion release paradigm.
  
  
  
  Both phantom and in vivo comparisons demonstrated that psMASE-ME-based R2and R2* had good agreement with those calculated by multiecho spin echo and gradient echo sequences. Scan-rescan tests showed good reproducibility. Moreover, muscle R2, R2', and R2* increased obviously from rest to cuff occlusion and decreased significantly after cuff release.
  
  
  
  It is feasible to obtain high temporally resolved R2, R2', and R2* simultaneously with the proposed psMASE-ME method. Magn Reson Med 77:766-773, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
authors.forename: Chengyan
authors.initials: C
authors.lastname: Wang
authors.affiliation: College of Engineering, Peking University, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Peking University First Hospital, Beijing, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Philips Healthcare, Suzhou, China.
authors.forename: He
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Radiology, Peking University First Hospital, Beijing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.affiliation: Philips Healthcare, Suzhou, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Jin
authors.affiliation: Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.|College of Engineering, Peking University, Beijing, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.|Department of Radiology, Peking University First Hospital, Beijing, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.affiliation: Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.|College of Engineering, Peking University, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fang
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007866:Leg / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D055815:Young Adult
keywords: dynamic imaging; moving estimation; periodic π pulse shifting; skeletal muscle