title: Impact of motion on T1 mapping acquired with inversion recovery fast spin echo and rapid spoiled gradient recalled-echo pulse sequences for delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) in volunteers.
abstract: OBJECTIVE
  To evaluate the impact of motion on T1 values acquired by using either inversion-recovery fast spin echo (IR-FSE) or three-dimensional (3D) spoiled gradient recalled-echo (SPGR) sequences for delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) in volunteers.
  
  
  METHODS
  Single-slice IR-FSE and 3D SPGR sequences were applied to perform dGEMRIC in five healthy volunteers. A mutual information-based approach was used to correct for image misregistration. Displacements were expressed as averaged Euclidean distances and angles. Averages of differences in goodness of fit (Deltachi(2)) tests and averages of relative differences in T1 values (DeltaT1) before and after motion correction were computed.
  
  
  RESULTS
  Maximum Euclidean distance was 3.5 mm and 1.2 mm for IR-FSE and SPGR respectively. Mean +/- SD of Deltachi(2) were 10.18 +/- 8.4 for IR-FSE and -1.37 +/- 5.5 for SPGR. Mean +/- SD of DeltaT1 were 0.008 +/- 0.0048 for IR-FSE and -0.002 +/- 0.019 for FSPGR. Pairwise comparison of Deltachi(2) values showed a significant difference for IR-FSE, but not for 3D-SPGR. Significantly greater variability in T1 values was also noted for IR-FSE than for 3D-SPGR.
  
  
  CONCLUSIONS
  Involuntary motion has a significant influence on T1 values acquired with IR-FSE, but not with 3D-SPGR in healthy volunteers.
authors.affiliation: Department of Medical Imaging, Mount Sinai Hospital and University Health Network, University of Toronto, Toronto, ON, Canada. studleru@uhbs.ch
authors.forename: Ueli
authors.initials: U
authors.lastname: Studler
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: White
authors.forename: Gustav
authors.initials: G
authors.lastname: Andreisek
authors.forename: Sheena
authors.initials: S
authors.lastname: Luu
authors.forename: Hai-Ling Margaret
authors.initials: HL
authors.lastname: Cheng
authors.forename: Marshall S
authors.initials: MS
authors.lastname: Sussman
mesh_terms: D000328:Adult; D002356:Cartilage / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology; D005260:Female; D005682:Gadolinium / Q000494:pharmacology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009038:Motion; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000473:pathology; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; D005682:Gadolinium