title: Initial experience with 3D isotropic high-resolution 3 T MR arthrography of the wrist.
abstract: BACKGROUND
  Our study was performed to evaluate the image quality of 3 T MR wrist arthrograms with attention to ulnar wrist structures, comparing image quality of isotropic 3D proton density fat suppressed turbo spin echo (PDFS TSE) sequence versus standard 2D 3 T sequences as well as comparison with 1.5 T MR arthrograms.
  
  
  METHODS
  Eleven consecutive 3 T MR wrist arthrograms were performed and the following sequences evaluated: 3D isotropic PDFS, repetition time/echo time (TR/TE) 1400/28.3 ms, voxel size 0.35x0.35x0.35 mm, acquisition time 5 min; 2D coronal sequences with slice thickness 2 mm: T1 fat suppressed turbo spin echo (T1FS TSE) (TR/TE 600/20 ms); proton density (PD) TSE (TR/TE 3499/27 ms). A 1.5 T group of 18 studies with standard sequences were evaluated for comparison. All MR imaging followed fluoroscopically guided intra-articular injection of dilute gadolinium contrast. Qualitative assessment related to delineation of anatomic structures between 1.5 T and 3 T MR arthrograms was carried out using Mann-Whitney test and the differences in delineation of anatomic structures among each sequence in 3 T group were analyzed with Wilcoxon signed-rank test. Quantitative assessment of mean relative signal intensity (SI) and relative contrast measurements was performed using Wilcoxon signed-rank test.
  
  
  RESULTS
  Mean qualitative scores for 3 T sequences were significantly higher than 1.5 T (p < 0.01), with isotropic 3D PDFS sequence having highest mean qualitative scores (p < 0.05). Quantitative analysis demonstrated no significant difference in relative signal intensity among the 3 T sequences. Significant differences were found in relative contrast between fluid-bone and fluid-fat comparing 3D and 2D PDFS (p < 0.01).
  
  
  CONCLUSIONS
  3D isotropic PDFS sequence showed promise in both qualitative and quantitative assessment, suggesting this may be useful for MR wrist arthrograms at 3 T. Primary reasons for diagnostic potential include the ability to make reformations in any obliquity to follow the components of ulnar side wrist structures including triangular fibrocartilage complex. Additionally, isotropic imaging provides thinner slice thickness with less partial volume averaging allowing for identification of subtle injuries.
authors.affiliation: University of California, Irvine, Department of Radiological Sciences, UCI Medical Center 101 The City Dr. South, Route 140, Orange, CA, 92686, USA. john.k.sutherland1@gmail.com.
authors.forename: John K
authors.initials: JK
authors.lastname: Sutherland
authors.affiliation: University of California, Irvine, Department of Radiological Sciences, UCI Medical Center 101 The City Dr. South, Route 140, Orange, CA, 92686, USA. nojyakki@gmail.com.
authors.forename: Taiki
authors.initials: T
authors.lastname: Nozaki
authors.affiliation: University of California, Irvine, Department of Radiological Sciences, UCI Medical Center 101 The City Dr. South, Route 140, Orange, CA, 92686, USA. kanekoyasuhito@gmail.com.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: University of California, Irvine, Department of Radiological Sciences and John Tu and Thomas Yuen Center for Functional Onco-Imaging Irvine, Irvine, CA, USA. hjyu@uci.edu.
authors.forename: Hon
authors.initials: H
authors.lastname: J Yu
authors.affiliation: University of California, Irvine, Department of Orthopaedic Surgery, Irvine, USA. grafijah@uci.edu.
authors.forename: Gregory
authors.initials: G
authors.lastname: Rafijah
authors.affiliation: Philips Medical Systems, Cleveland, OH, USA. dave.hitt@philips.com.
authors.forename: David
authors.initials: D
authors.lastname: Hitt
authors.affiliation: University of California, Irvine, Department of Radiological Sciences, UCI Medical Center 101 The City Dr. South, Route 140, Orange, CA, 92686, USA. hiroshi@uci.edu.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshioka
mesh_terms: D000293:Adolescent; D000328:Adult; D001175:Arthrography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014953:Wrist / Q000000981:diagnostic imaging*; D055815:Young Adult