title: Ex vivo quantitative multiparametric MRI mapping of human meniscus degeneration.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of T1, T1ρ, T2, T2*, and UTE-T2* (ultrashort-echo time-enhanced T2*) mapping in the refined graduation of human meniscus degeneration with histology serving as standard-of-reference.
  
  
  METHODS
  This IRB-approved intra-individual comparative ex vivo study was performed on 24 lateral meniscus body samples obtained from 24 patients undergoing total knee replacement. Samples were assessed on a 3.0-T MRI scanner using inversion-recovery (T1), spin-lock multi-gradient-echo (T1ρ), multi-spin-echo (T2) and multi-gradient-echo (T2* and UTE-T2*) sequences to determine relaxation times of quantitative MRI (qMRI) parameters. Relaxation times were calculated on the respective maps, averaged to the entire meniscus and to its zones. Histologically, samples were analyzed on a four-point score according to Williams (0-III). QMRI results and Williams (sub)scores were correlated using Spearman's ρ, while Williams grade-dependent differences were assessed using Kruskal-Wallis and Dunn's tests. Sensitivities and specificities in the detection of intact (Williams grade [WG]-0) and severely degenerate meniscus (WG-II-III) were calculated.
  
  
  RESULTS
  Except for T2*, significant increases in qMRI parameters with increasing Williams grades were observed. T1, T1ρ, T2, and UTE-T2* exhibited high sensitivity and variable specificity rates. Significant marked-to-strong correlations were observed for these parameters with each other, with histological WGs and the subscores tissue integrity and cellularity.
  
  
  CONCLUSIONS
  QMRI mapping holds promise in the objective evaluation of human meniscus. Although sufficient discriminatory power of T1, T1ρ, T2, and UTE-T2* was only demonstrated for the histological extremes, these data may aid in the future MRI-based parameterization and quantification of human meniscus degeneration.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany. snebelung@ukaachen.de.
authors.forename: Sven
authors.initials: S
authors.lastname: Nebelung
authors.affiliation: Department of Orthopaedics, Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Tingart
authors.affiliation: Institute of Anatomy and Cell Biology, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pufe
authors.affiliation: Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Kuhl
authors.affiliation: Department of Orthopaedics, Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Jahr
authors.affiliation: Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Truhn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D011446:Prospective Studies; D000070600:Tibial Meniscus Injuries / Q000000981:diagnostic imaging*
keywords: Degeneration; Histology; MRI parameters; Meniscus; Quantitative MRI