title: Detection of Active Sacroiliitis with Ankylosing Spondylitis through Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging.
abstract: OBJECTIVE
  To confirm feasibility and assess intravoxel incoherent motion (IVIM) to differentiate active sacroiliitis and ankylosing spondylitis..
  
  
  METHODS
  Forty-one patients were divided into two groups, an active group (n = 20) and a chronic group (n = 21), according to the Bath Ankylosing Spondylitis (AS) Disease Activity Index (BASDAI) and laboratory parameters. In addition, 21 healthy volunteers were chosen as the control group. Tissue diffusivity (Dslow), perfusion fraction (f), and pseudo-diffusion coefficient (Dfast) values were obtained for all three groups. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters.
  
  
  RESULTS
  There was good interobserver agreement on the measurements between the two observers. The optimal cut-off values (with respective AUC, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio) between active and chronic groups were Dslow = 0.53 × 10(-3) mm(2)/s (0.976, 90%, 95.2%, 18.9, 0.10) and f = 0.09 (0.545, 20%, 95.5%, 4.2, 0.84), and between chronic and control groups were Dslow = 0.22 × 10(-3) mm(2)/s (0.517, 9.52%, 100%, no number, 0.9) and f = 0.09 (0.935, 95.24%, 80.95%, 5, 0.059).
  
  
  CONCLUSIONS
  Dslow and f of IVIM diffusion-weighted (DW)-MRI in AS show a significant difference in the values of diffusion of water molecules and fractional perfusion-related volume among the three groups.
  
  
  CONCLUSIONS
  • D slow can be used to differentiate the activity of AS. • With perfusion fraction, the sensitivity of differentiating the AS activity is improved. • IVIM DWI plays an important role in detecting the activity in patients with AS.
authors: Department of Radiology, Third Affiliated Hospital of Southern Medical University, Academy of Orthopedics, 183 Zhongshan Da Dao Xi, Guangdong Province, Guangzhou, 510630, China.
authors: Ying-hua
authors: YH
authors: Zhao
authors: Shao-lin
authors: SL
authors: Li
authors: Zai-yi
authors: ZY
authors: Liu
authors: Xin
authors: X
authors: Chen
authors: Xiang-cheng
authors: XC
authors: Zhao
authors: Shao-yong
authors: SY
authors: Hu
authors: Zhen-hua
authors: ZH
authors: Liu
authors: Ying-jie Mei
authors: YJ
authors: M S
authors: Queenie
authors: Q
authors: Chan
authors: Chang-hong
authors: CH
authors: Liang
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D011446:Prospective Studies; D015203:Reproducibility of Results; D012446:Sacroiliac Joint / Q000473:pathology*; D058566:Sacroiliitis / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013167:Spondylitis, Ankylosing / Q000175:diagnosis*; D055815:Young Adult