title: An assessment of the intra- and inter-reliability of the lumbar paraspinal muscle parameters using CT scan and magnetic resonance imaging.
abstract: METHODS
  A reliability study was conducted.
  
  
  OBJECTIVE
  To estimate the intra- and intermeasurement errors in the measurements of functional cross-sectional area (FCSA), density, and T2 signal intensity of paraspinal muscles using computed tomography (CT) scan and magnetic resonance imaging (MRI).
  
  
  BACKGROUND
  CT scan and MRI had been used widely to measure the cross-sectional area and degeneration of the back muscles in spine and muscle research. But there is still no systemic study to analyze the reliability of these measurements.
  
  
  METHODS
  This study measured the FCSA and fatty infiltration (density on CT scan and T2 signal intensity on MRI) of the paraspinal muscles at L3-L4, L4-L5, and L5-S1 in 29 patients with chronic low back pain. Two experienced musculoskeletal radiologists and one superior spine surgeon traced the region of interest twice within 3 weeks for measurement of the intra- and interobserver reliability.
  
  
  RESULTS
  The intraclass correlation coefficients (ICCs) of the intra-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. The ICCs of the inter-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. There were no significant differences between CT scan and MRI in reliability results, except in the relative standard error of fatty infiltration measurement. The ICCs of the FCSA measurement between CT scan and MRI ranged from poor to good.
  
  
  CONCLUSIONS
  The reliabilities of the CT scan and MRI for measuring the FCSA and fatty infiltration of the atrophied lumbar paraspinal muscles were acceptable. It was reliable for using uniform one image method for a single paraspinal muscle evaluation study. And the authors preferred to advise the MRI other than CT scan for paraspinal muscles measurements of FCSA and fatty infiltration.
authors.affiliation: Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Hu
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.forename: Feng-Dong
authors.initials: FD
authors.lastname: Zhao
authors.forename: Xiang-Qian
authors.initials: XQ
authors.lastname: Fang
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Zhou
authors.forename: Shun-Wu
authors.initials: SW
authors.lastname: Fan
mesh_terms: D050154:Adiposity; D000328:Adult; D000368:Aged; D002681:China; D002908:Chronic Disease; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D009133:Muscular Atrophy / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed