title: Detection of osteophytes and subchondral cysts in the knee with use of tomosynthesis.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of tomosynthesis in depicting osteophytes and subchondral cysts, with use of magnetic resonance (MR) imaging as the reference, and to test whether the lesions detected at radiography and tomosynthesis are associated with pain.
  
  
  METHODS
  The study was approved by local institutional review board, and all subjects gave written informed consent. Forty subjects (80 knees) older than 40 years were recruited irrespective of knee pain or radiographic osteoarthritis. Knees were imaged with radiography, tomosynthesis, and MR imaging. Presence of osteophytes and subchondral cysts in four locations of tibiofemoral joint (medial and lateral femur and tibia) was recorded. Knee pain was assessed by using the Western Ontario and McMaster University pain subscale.
  
  
  RESULTS
  MR imaging depicted 171 osteophytes and 51 subchondral cysts. Tomosynthesis had a higher sensitivity for osteophyte detection in left and right lateral femur (0.96 vs 0.75, P = .025, and 1.00 vs 0.71, P = .008, respectively), right medial femur (0.94 vs 0.72, P = .046), and right lateral tibia (1.00 vs 0.83, P = .046). For subchondral cyst detection, the sensitivity of tomosynthesis was 0.14-1.00 and that of radiography was 0.00-0.56. Both modalities had similar specificity for both lesions. Subjects with tomosynthesis-depicted osteophytes (odds ratio, 4.2-6.4; P = .001-.011) and medially located subchondral cysts (odds ratio, 6.7-17.8; P = .004-.03) were more likely to feel pain than those without. However, radiography-depicted osteophytes were more strongly associated with pain than were tomosynthesis-depicted osteophytes.
  
  
  CONCLUSIONS
  Tomosynthesis depicted more osteophytes and subchondral cysts than did radiography. Subjects with tomosynthesis-depicted osteophytes and subchondral cysts were more likely to feel pain than those without such lesions.
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA 02118, USA. dhayashi@bu.edu
authors.forename: Daichi
authors.initials: D
authors.lastname: Hayashi
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Frank W
authors.initials: FW
authors.lastname: Roemer
authors.forename: David J
authors.initials: DJ
authors.lastname: Hunter
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Avinash M
authors.initials: AM
authors.lastname: Katur
authors.forename: Ali
authors.initials: A
authors.lastname: Guermazi
mesh_terms: D000328:Adult; D000368:Aged; D001845:Bone Cysts / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D054850:Osteophyte / Q000000981:diagnostic imaging* / Q000473:pathology; D010147:Pain Measurement; D016012:Poisson Distribution; D011859:Radiography; D012044:Regression Analysis; D012680:Sensitivity and Specificity