title: New dynamic three-dimensional MRI technique for shoulder kinematic analysis.
abstract: OBJECTIVE
  To establish a new imaging technique using dynamic MRI three-dimensional (3D) volumetric acquisition in real-time, on six normal shoulders for the analysis of the 3D shoulder kinematics during continuous motion.
  
  
  METHODS
  At first, a standard static acquisition was performed. Then, fast images were obtained with a multi-slice 3D balanced gradient echo sequence to get a real time series during the initial phase of shoulder abduction. Subsequently, the images were reconstructed; registered and the translational patterns of the humeral head relative to the glenoid and the size of the subacromial space were calculated. Additionally, the intraobserver reproducibility was tested.
  
  
  RESULTS
  The maximal abduction was on average 43° (30° to 60°) and the mean width of the subacromial space was 7.7 mm (SD: ±1.2 mm). Difference between extreme values and average values was low, respectively 2.5 mm on X-axis, 2 mm on Y-axis, 1.4 mm for the width of the subacromial space and 1.2° for the measure of the glenohumeral abduction.
  
  
  CONCLUSIONS
  This study reported a dynamic MRI protocol for the monitoring of shoulder 3D kinematics during continuous movement. The results suggest that there is no superior shift of the humeral head during the first phase of abduction.
authors.affiliation: Laboratory of Biomechanics, Arts et métiers ParisTech, France.; Orthopaedic Surgery and traumatology, European Hospital Georges Pompidou, APHP, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Pierrart
authors.forename: Marie-Martine
authors.initials: MM
authors.lastname: Lefèvre-Colau
authors.forename: Wafa
authors.initials: W
authors.lastname: Skalli
authors.forename: Valérie
authors.initials: V
authors.lastname: Vuillemin
authors.forename: Emmanuel H
authors.initials: EH
authors.lastname: Masmejean
authors.forename: Charles A
authors.initials: CA
authors.lastname: Cuénod
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gregory
mesh_terms: D001696:Biomechanical Phenomena; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010865:Pilot Projects; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D012785:Shoulder Joint / Q000033:anatomy & histology* / Q000502:physiology
keywords: 3D kinematic; real time MRI; shoulder kinematic