title: Optimized cartilage visualization using 7-T sodium ((23)Na) imaging after patella dislocation.
abstract: OBJECTIVE
  Retropatellar cartilage lesions often occur in the course of recurrent patella dislocation. Aim of this study was to develop a more detailed method for examining cartilage tissue, in order to reduce patient discomfort and time of care.
  
  
  METHODS
  For detailed diagnosing, a 7-T MRI of the knee joint and patella was performed in nine patients, with mean age of 26.4 years, after patella dislocation to measure the cartilage content in three different regions of interest of the patella. Axial sodium ((23)Na) images were derived from an optimized 3D GRE sequence on a 7-T MR scanner. Morphological cartilage grading was performed, and sodium signal-to-noise ratio (SNR) values were calculated. Mean global sodium values and SNR were compared between patients and volunteers.
  
  
  RESULTS
  Two out of nine patients showed a maximum cartilage defect of International Cartilage Repair Society (ICRS) grade 3, three of grade 2, three of  grade 1, and one patient showed no cartilage defect. The mean SNR in sodium images for cartilage was 13.4 ± 2.5 in patients and 14.6 ± 3.7 in volunteers (n.s.). A significant negative correlation between age and global sodium SNR for cartilage was found in the medial facet (R = -0.512; R (2) = 0.26; p = 0.030). Mixed-model ANOVA yielded a marked decrease of the sodium SNR, with increasing grade of cartilage lesions (p < 0.001).
  
  
  CONCLUSIONS
  Utilization of the (23)Na MR imaging will make earlier detection of alterations to the patella cartilage after dislocation possible and will help prevent subsequent disease due to start adequate therapy earlier in the rehabilitation process.
  
  
  METHODS
  II.
authors.affiliation: Department of Traumatology, Center for Joints and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria. harald.widhalm@meduniwien.ac.at.
authors.forename: Harald K
authors.initials: HK
authors.lastname: Widhalm
authors.affiliation: Department of Radiology, MR Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Apprich
authors.affiliation: Department of Radiology, MR Center, Medical University of Vienna, Vienna, Austria.|Department of Trauma Surgery, University Hospital of Erlangen, Erlangen, Germany.
authors.forename: Goetz H
authors.initials: GH
authors.lastname: Welsch
authors.affiliation: Department of Radiology, MR Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Zbyn
authors.affiliation: Department of Orthopaedic Surgery, Medical University of Graz, Graz, Austria.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sadoghi
authors.affiliation: Department of Traumatology, Center for Joints and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: György
authors.initials: G
authors.lastname: Vekszler
authors.affiliation: Department of Traumatology, Center for Joints and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Hamböck
authors.affiliation: Department of Radiology, MR Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.affiliation: Department of Traumatology, Center for Joints and Cartilage, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hajdu
authors.affiliation: Department of Radiology, MR Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
mesh_terms: D000328:Adult; D002357:Cartilage Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology / Q000601:surgery; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010329:Patella / Q000000981:diagnostic imaging* / Q000473:pathology; D031222:Patellar Dislocation / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D019275:Radiopharmaceuticals; D017670:Sodium Compounds; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D017670:Sodium Compounds
keywords: 7 T; Cartilage; Glycosaminoglycans; Magnetic resonance imaging; Patella dislocation; Sodium