title: MR arthrography of the hip: diagnostic performance of a dedicated water-excitation 3D double-echo steady-state sequence to detect cartilage lesions.
abstract: OBJECTIVE
  The objective of our study was to compare the diagnostic performance of a dedicated cartilage MR sequence (water-excitation 3D double-echo steady-state) with a standard MR sequence (T1-weighted spin-echo) in detecting articular cartilage lesions of the hip after intraarticular injection of gadopentetate dimeglumine.
  
  
  METHODS
  In 50 MR arthrograms of the hip joint obtained in 47 consecutive patients, a sagittal 3D double-echo steady-state sequence (TR/TE, 24/6.5; flip angle, 25 degrees ) was compared with a sagittal T1-weighted spin-echo sequence (350/14). Two musculoskeletal radiologists independently evaluated articular cartilage. Sensitivity and specificity for detecting cartilage defects were calculated for those hips that underwent open surgery (n = 21). Lesion conspicuity was retrospectively reviewed and graded between 1 (not visible) and 5 (well defined).
  
  
  RESULTS
  At surgery, a total of 26 lesions of the acetabular (n = 20) and femoral (n = 6) cartilage were found. For the 3D double-echo steady-state and T1-weighted spin-echo sequences, sensitivities and specificities for cartilage lesion detection were 58% and 88% and 81% and 81% for reviewer 1 and 62% and 94% and 62% and 100% for reviewer 2, respectively. Lesion conspicuity was significantly superior (p = 0.036) for the 3D double-echo steady-state sequence (mean grade, 3.4) compared with the T1-weighted spin-echo sequence (mean grade, 3.0). The kappa value was fair for the 3D double-echo steady-state sequence (kappa = 0.40) and moderate for the T1-weighted spin-echo sequence (kappa = 0.55).
  
  
  CONCLUSIONS
  The 3D double-echo steady-state sequence optimized for cartilage imaging improves lesion conspicuity but does not improve diagnostic performance.
authors.affiliation: Department of Radiology, University Hospital Balgrist, Forchstrasse 340, Zurich CH-8008, Switzerland.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Knuesel
authors.forename: Christian W A
authors.initials: CW
authors.lastname: Pfirrmann
authors.forename: Hubert P
authors.initials: HP
authors.lastname: Noetzli
authors.forename: Claudio
authors.initials: C
authors.lastname: Dora
authors.forename: Marco
authors.initials: M
authors.lastname: Zanetti
authors.forename: Juerg
authors.initials: J
authors.lastname: Hodler
authors.forename: Bernd
authors.initials: B
authors.lastname: Kuehn
authors.forename: Marius R
authors.initials: MR
authors.lastname: Schmid
mesh_terms: D000328:Adult; D000368:Aged; D002357:Cartilage Diseases / Q000175:diagnosis*; D002358:Cartilage, Articular / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006621:Hip Joint / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA