title: Semiquantitative assessment of subchondral bone marrow edema-like lesions and subchondral cysts of the knee at 3T MRI: a comparison between intermediate-weighted fat-suppressed spin echo and Dual Echo Steady State sequences.
abstract: BACKGROUND
  Choice of appropriate MR pulse sequence is important for any research studies using imaging-derived data. The aim of this study was to compare semiquantitative assessment of subchondral bone marrow edema-like lesions and subchondral cysts using intermediate-weighted (IW) fat-suppressed (fs) spin echo and Dual Echo Steady State (DESS) sequences on 3 T MRI.
  
  
  METHODS
  Included were 201 subjects aged 35-65 with frequent knee pain. 3T MRI was performed with the same sequence protocol as in the Osteoarthritis Initiative (OAI). In a primary reading subchondral bone marrow edema-like lesions were assessed according to the WORMS system. Two hundred subregions with such lesions were randomly chosen. The extent of subchondral bone marrow edema-like lesions was re-evaluated separately using sagittal IW fs and DESS sequences according to WORMS. Lesion size and confidence of the differentiation between subchondral bone marrow edema-like lesions and subchondral cysts located within or adjacent to them was rated from 0 to 3. Wilcoxon signed-rank tests and chi-square statistics were used to examine differences between the two sequences.
  
  
  RESULTS
  Of 200 subchondral bone marrow edema-like lesions detected by IW fs sequence, 93 lesions (46.5%) were not depicted by the DESS sequence. The IW fs sequence depicted subchondral bone marrow edema-like lesions to a larger extent than DESS (p < 0.0001), and the opposite was true for subchondral cysts. Confidence scores for differentiation of the two types of lesions were not significantly different between the two sequences.
  
  
  CONCLUSIONS
  In direct comparison the IW fs sequence depicts more subchondral bone marrow edema-like lesions and better demonstrate the extent of their maximum size. The DESS sequence helps in the differentiation of subchondral bone marrow edema-like lesions and subchondral cysts. The IW fs sequence should be used for determination of lesion extent whenever the size of subchondral bone marrow edema-like lesions is the focus of attention.
authors: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA 02118, USA. dhayashi@bu.edu
authors: Daichi
authors: D
authors: Hayashi
authors: Ali
authors: A
authors: Guermazi
authors: C Kent
authors: CK
authors: Kwoh
authors: Michael J
authors: MJ
authors: Hannon
authors: Carolyn
authors: C
authors: Moore
authors: John M
authors: JM
authors: Jakicic
authors: Stephanie M
authors: SM
authors: Green
authors: Frank W
authors: FW
authors: Roemer
mesh_terms: D000328:Adult; D000368:Aged; D001845:Bone Cysts / Q000150:complications / Q000473:pathology*; D001855:Bone Marrow Diseases / Q000150:complications / Q000175:diagnosis*; D004487:Edema / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000150:complications / Q000473:pathology; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels
chemical_list: D013113:Spin Labels