title: Comparison of Multi-Echo Dixon Methods with Volume Interpolated Breath-Hold Gradient Echo Magnetic Resonance Imaging in Fat-Signal Fraction Quantification of Paravertebral Muscle.
abstract: OBJECTIVE
  To assess whether multi-echo Dixon magnetic resonance (MR) imaging with simultaneous T2* estimation and correction yields more accurate fat-signal fraction (FF) measurement of the lumbar paravertebral muscles, in comparison with non-T2*-corrected two-echo Dixon or T2*-corrected three-echo Dixon, using the FF measurements from single-voxel MR spectroscopy as the reference standard.
  
  
  METHODS
  Sixty patients with low back pain underwent MR imaging with a 1.5T scanner. FF mapping images automatically obtained using T2*-corrected Dixon technique with two (non-T2*-corrected), three, and six echoes, were compared with images from single-voxel MR spectroscopy at the paravertebral muscles on levels L4 through L5. FFs were measured directly by two radiologists, who independently drew the region of interest on the mapping images from the three sequences.
  
  
  RESULTS
  A total of 117 spectroscopic measurements were performed either bilaterally (57 of 60 subjects) or unilaterally (3 of 60 subjects). The mean spectroscopic FF was 14.3 ± 11.7% (range, 1.9-63.7%). Interobserver agreement was excellent between the two radiologists. Lin's concordance correlation between the spectroscopic findings and all the imaging-based FFs were statistically significant (p < 0.001). FFs obtained from the T2*-corrected six-echo Dixon sequences showed a significantly better concordance with the spectroscopic data, with its concordance correlation coefficient being 0.99 and 0.98 (p < 0.001), as compared with two- or three-echo methods.
  
  
  CONCLUSIONS
  T2*-corrected six-echo Dixon sequence would be a better option than two- or three-echo methods for noninvasive quantification of lumbar muscle fat quantification.
authors.affiliation: Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
authors.forename: Yeon Hwa
authors.initials: YH
authors.lastname: Yoo
authors.affiliation: Department of Orthopedic Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
authors.forename: Hak-Sun
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
authors.forename: Choon-Sik
authors.initials: CS
authors.lastname: Yoon
authors.affiliation: Healthcare Sector, Siemens Ltd., Seoul 03737, Korea.
authors.forename: Mun Young
authors.initials: MY
authors.lastname: Paek
authors.affiliation: Biostatistics Collaboration Lab, Yonsei University College of Medicine, Seoul 03722, Korea.
authors.forename: Hanna
authors.initials: H
authors.lastname: Yoo
authors.affiliation: Healthcare Sector, Siemens AG, Erlangen 91052, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kannengiesser
authors.affiliation: Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
authors.forename: Tae-Sub
authors.initials: TS
authors.lastname: Chung
authors.affiliation: Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.
authors.forename: Ho-Taek
authors.initials: HT
authors.lastname: Song
authors.affiliation: Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.
authors.forename: Jin-Suck
authors.initials: JS
authors.lastname: Suh
authors.affiliation: Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.
authors.forename: Sungjun
authors.initials: S
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017116:Low Back Pain / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000000981:diagnostic imaging; D011859:Radiography; D013116:Spinal Cord
keywords: Dixon; Fat-signal fraction; Magnetic resonance imaging; Muscle; Spine