title: Can a single isotropic 3D fast spin echo sequence replace three-plane standard proton density fat-saturated knee MRI at 1.5 T?
abstract: OBJECTIVE
  To assess whether a single isotropic three-dimensional (3D) fast spin echo (FSE) proton density fat-saturated (PD FS) sequence reconstructed in three planes could replace the three PD (FS) sequences in our standard protocol at 1.5 T (Siemens Avanto, Erlangen, Germany).
  
  
  METHODS
  A 3D FSE PD water excitation sequence was included in the protocol for 95 consecutive patients referred for routine knee MRI. This was used to produce offline reconstructions in axial, sagittal and coronal planes. Two radiologists independently assessed each case twice, once using the standard MRI protocol and once replacing the standard PD (FS) sequences with reconstructions from the 3D data set. Following scoring, the observer reviewed the 3D data set and performed multiplanar reformats to see if this altered confidence. The menisci, ligaments and cartilage were assessed, and statistical analysis was performed using the standard sequence as the reference standard.
  
  
  RESULTS
  The reporting accuracy was as follows: medial meniscus (MM) = 90.9%, lateral meniscus (LM) = 93.7%, anterior cruciate ligament (ACL) = 98.9% and cartilage surfaces = 85.8%. Agreement among the readers was for the standard protocol: MM kappa = 0.91, LM = 0.89, ACL = 0.98 and cartilage = 0.84; and for the 3D protocol: MM = 0.86, LM = 0.77, ACL = 0.94 and cartilage = 0.64.
  
  
  CONCLUSIONS
  A 3D PD FSE sequence reconstructed in three planes gives reduced accuracy and decreased concordance among readers compared with conventional sequences when evaluating the menisci and cartilage with a 1.5-T MRI scanner.
  
  
  CONCLUSIONS
  Using the existing 1.5-T MR systems, a 3D FSE sequence should not replace two-dimensional sequences.
authors.affiliation: 1 Musculoskeletal Centre X-Ray Department, Leeds Teaching Hospitals Trust, Chapel Allerton Hospital, Leeds, UK.
authors.forename: B
authors.initials: B
authors.lastname: Pass
authors.affiliation: 1 Musculoskeletal Centre X-Ray Department, Leeds Teaching Hospitals Trust, Chapel Allerton Hospital, Leeds, UK.|2 Leeds Musculoskeletal Biomedical Research Unit, University of Leeds, Leeds, UK.
authors.forename: P
authors.initials: P
authors.lastname: Robinson
authors.affiliation: 3 Centre for Imaging Sciences, University of Manchester, Manchester, UK.
authors.forename: R
authors.initials: R
authors.lastname: Hodgson
authors.affiliation: 1 Musculoskeletal Centre X-Ray Department, Leeds Teaching Hospitals Trust, Chapel Allerton Hospital, Leeds, UK.|2 Leeds Musculoskeletal Biomedical Research Unit, University of Leeds, Leeds, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Grainger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods / Q000592:standards; D007718:Knee Injuries / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology; D008875:Middle Aged; D000070600:Tibial Meniscus Injuries; D055815:Young Adult