title: Comparison of MR-arthrography and MDCT-arthrography for detection of labral and articular cartilage hip pathology.
abstract: OBJECTIVE
  To compare the diagnostic ability of MR arthrography (MRa) and MDCT arthrography (CTa) in depicting surgically proven hip labral tears and articular cartilage degradation.
  
  
  METHODS
  Labral pathology and articular cartilage were prospectively evaluated with MRa and CTa in 14 hips of 10 patients. The findings were evaluated by two independent observers (a musculoskeletal fellow and one senior musculoskeletal radiologist). Sensitivity, specificity, accuracy, and positive predictive value were determined using arthroscopic and open surgery findings as the standard of reference. Interobserver agreement was recorded. All images were assessed for the presence of a labral tear (according to Czerny classification) and for cartilage erosion using a 3 point scale for both methods: 1 = complete visualization-sharp edges, 2 = blurred edges fissuring-partial defects, 3 = exposed bone. The same classification was applied surgically.
  
  
  RESULTS
  Disagreement between the senior observer and the fellow observer was recorded in three cases of labral tearing with MRa and six with CTa. Disagreement was also found in four cases of cartilage erosion with both MRa and CTa. The percent sensitivity, specificity, accuracy, and positive predictive value for correctly assessing the labral tear were as follows for MRa/CTa, respectively: 100/15, 50/13, 90/14, and 90/13 (P < 0.05). The same values for cartilage assessment were 63/66, 33/40, 50/57 and 55/66 (P > 0.05).
  
  
  CONCLUSIONS
  Interobserver reproducibility with MRa is very good for labral tearing assessment. MRa is better for assessing labral tears. CTa shows better, but not statistically significant, demonstration of the articular cartilage.
authors.affiliation: Department of Radiology, University Hospital, University of Crete, Stavrakia, Heraklion, Greece. perdikakis_ev@yahoo.gr
authors.forename: Evangelos
authors.initials: E
authors.lastname: Perdikakis
authors.forename: Theofilos
authors.initials: T
authors.lastname: Karachalios
authors.forename: Pavlos
authors.initials: P
authors.lastname: Katonis
authors.forename: Apostolos
authors.initials: A
authors.lastname: Karantanas
mesh_terms: D020083:Acquired Hyperostosis Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging; D000328:Adult; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000293:injuries / Q000473:pathology*; D005260:Female; D057925:Femoracetabular Impingement / Q000175:diagnosis / Q000000981:diagnostic imaging; D006618:Hip Dislocation, Congenital / Q000175:diagnosis / Q000000981:diagnostic imaging; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D055815:Young Adult