title: 90°-flip-angle three-dimensional double-echo steady-state (3D-DESS) magnetic resonance imaging of the knee: isovoxel cartilage imaging at 3T.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether 3D-double echo steady state (3D-DESS) with improved contrast by setting the FA (Flip angle) at 90° is useful in 3D isotropic cartilage imaging of the knee at 3T.
  
  
  METHODS
  Imaging was performed in 10 healthy volunteers using 3 methods: with 3D-DESS using FA of 25° and 90°, and with true fast imaging with steady-state precession (True-FISP). The signal-to-noise ratio (SNR) of the synovial fluid and cartilage, and contrast-to-noise ratio (CNR) were measured, and mean values were compared. Visual assessment of artifacts was performed with the cartilage divided into 6 regions.
  
  
  RESULTS
  There were no significant differences in synovial fluid SNR in the comparison between FA-90° 3D-DESS and True-FISP (P=0.364). A significantly higher cartilage SNR was observed with FA-90° 3D-DESS than with True-FISP (P=0.031). There were no significant differences in synovial fluid-cartilage CNR between FA-90° 3D-DESS and True-FISP (P=0.892). In the evaluation of artifacts, FA-90° 3D-DESS imaging showed a significantly higher score than True-FISP imaging in the patella and trochlea cartilage (P<0.001, P<0.002).
  
  
  CONCLUSIONS
  FA-90° 3D-DESS is useful in 3D isotropic cartilage imaging of the knee at 3T.
authors.affiliation: Ishikawa Clinic, 46-1 Shimokamo-Umenoki-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-0851, Japan; Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa 920-0942, Japan. Electronic address: smoyari@yahoo.co.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Moriya
authors.affiliation: Department of Radiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan. Electronic address: yukio.miki@med.osaka-cu.ac.jp.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, 54 Shogoin-kawahara-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan. Electronic address: mitsuk@kuhp.kyoto-u.ac.jp.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kanagaki
authors.affiliation: Oike Clinic, 11 Nishinokyo-Shimoai-cho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8436, Japan. Electronic address: ynoma2000jp@yahoo.co.jp.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Matsuno
authors.affiliation: Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa 920-0942, Japan. Electronic address: ramiyati@mhs.mp.kanazawa-u.ac.jp.
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007719:Knee Joint / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D059629:Signal-To-Noise Ratio; D013582:Synovial Fluid
keywords: 3D isotropic imaging; 3Tesla; Artifact; Cartilage; Knee; MRI