title: Volumetric and semiquantitative assessment of MRI-detected subchondral bone marrow lesions in knee osteoarthritis: a comparison of contrast-enhanced and non-enhanced imaging.
abstract: OBJECTIVE
  Aim was to compare volumetric and semi-quantitative (SQ) measurements of subchondral bone marrow lesions (BMLs) on non-fat-suppressed (FS) T1-weighted (w), T1-w FS contrast enhanced (CE) and proton density (PD)-w FS images in order to define which sequence depicts the lesions to their maximum extent and if T1-w FS CE images and PD-w FS images may be used interchangeably to assess BMLs in a volumetric or SQ fashion.
  
  
  METHODS
  Thirty-two patients with clinical knee osteoarthritis (OA) were scanned on a standard 1.5 T MRI system. A total of 47 BMLs were identified and were manually segmented on all three sequences. BMLs were also assessed semiquantitatively using the Whole Organ Magnetic Resonance Imaging Score (WORMS). The volumetric and SQ results were compared across the three imaging sequences using paired t-tests.
  
  
  RESULTS
  Eighty-three percent of the lesions appeared largest on the PD-w FS sequence. Significant differences were observed for volumetric measurements between all three sequences (P < 0.001), however the mean volume difference between PD-w FS and T1-w FS CE (38%) was much smaller than for non-FS T1-w and PD-w FS/T1-w FS CE sequences (195% and 114%, respectively). Significant differences in WORMS scores were noted between PD-w FS and non-FS T1-w images and between T1-w FS CE and non-FS T1-w images (P < 0.001), but no significant difference was observed between PD-w FS and T1-w FS CE images.
  
  
  CONCLUSIONS
  Our findings suggest that the T1-w FS CE and PD-w FS sequences may be interchangeably used for quantitative volumetric and SQ assessment of BMLs.
authors.affiliation: Department of Radiology, Boston University Medical Center, Boston, MA 02118, USA. froemer@bu.edu
authors.forename: F W
authors.initials: FW
authors.lastname: Roemer
authors.forename: H
authors.initials: H
authors.lastname: Khrad
authors.forename: D
authors.initials: D
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Jara
authors.forename: A
authors.initials: A
authors.lastname: Ozonoff
authors.forename: A K
authors.initials: AK
authors.lastname: Fotinos-Hoyer
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
mesh_terms: D000368:Aged; D001853:Bone Marrow; D001855:Bone Marrow Diseases / Q000473:pathology*; D006801:Humans; D007719:Knee Joint; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology*; D013223:Statistics as Topic