title: MR Imaging with T2*- mapping for improved acetabular cartilage assessment in FAI-a case report with arthroscopic correlation.
abstract: Articular cartilage assessment in femoroacetabular impingement (FAI) is challenging. Recent studies on T2* relaxation time mapping suggest the technique may be useful in diagnosing cartilage damage. The purpose of this case report is to describe how quantitative T2*-mapping may improve cartilage assessment of the acetabulum in patients with FAI. MR arthrography was performed at 3 Tesla (T) using intra-articular Gadolinium and a T2* mapping protocol. Data from the acetabular cartilage was separated from femoral head cartilage data and then superimposed on a flattened, map projection representation of the patient's acetabulum. The areas of unhealthy cartilage observed at the time of arthroscopy - including debonding and delamination - were seen preoperatively at the same anatomic locations as areas of decreased T2* values. T2* mapping values provided a non-invasive assessment of the acetabular articular cartilage. A flattened acetabular map projection allowed for anatomic visualization of areas of unhealthy cartilage.
  
  
  METHODS
  Level IV.
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, 2512 South 7th Street, Minneapolis, MN, 55454, USA.
authors.forename: P
authors.initials: P
authors.lastname: Morgan
authors.affiliation: Department of Radiology, University of Minnesota, 2021, Sixth Street SE, Minneapolis, MN 55455, USA.
authors.forename: S
authors.initials: S
authors.lastname: Spiridonov
authors.affiliation: Department of Psychology and Neuroscience, Maastricht University, P.O. Box 616 6200 MD Maastricht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Goebel
authors.affiliation: Department of Radiology, University of Minnesota, 2021, Sixth Street SE, Minneapolis, MN 55455, USA.
authors.forename: M
authors.initials: M
authors.lastname: Nissi
authors.affiliation: Department of Orthopedic Surgery, Charles University, Budínova 2, Praha 8, 180 81, Czech Republic.
authors.forename: R
authors.initials: R
authors.lastname: Frei
authors.affiliation: Department of Radiology, University of Minnesota, 2021, Sixth Street SE, Minneapolis, MN 55455, USA. Electronic address: eller001@umn.edu.
authors.forename: J
authors.initials: J
authors.lastname: Ellermann
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D002358:Cartilage, Articular / Q000601:surgery*; D057925:Femoracetabular Impingement / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male
keywords: Arthroscopy; Cartilage; FAI; Hip; MRI; T2*-mapping