title: Correlation between intravoxel incoherent motion MR parameters and MR nodular grade of parotid glands in patients with Sjögren's syndrome: A pilot study.
abstract: OBJECTIVE
  To explore the correlation between intravoxel incoherent motion (IVIM) magnetic resonance (MR) parameters and MR nodular grade of parotid glands in patients with Sjögren's syndrome (SS).
  
  
  METHODS
  A total of 31 consecutive patients with SS and 28 gender- and age-matched healthy volunteers underwent bilateral parotid 3.0T MR examination including the IVIM sequence (9 b values, 0-800s/mm2). The apparent diffusion coefficient (ADC), diffusion coefficient D, pseudo-diffusion coefficient D*, and perfusion fraction f of bilateral parotid glands were obtained, and the nodular grade of each parotid gland was evaluated according to the MR morphological appearance.
  
  
  RESULTS
  Sixty-two parotid glands in 31 patients with SS consisted of 32, 14, 8, and 8 parotid glands at MR nodular grades 0, 1, 2, and 3, respectively. In parotid glands of grade 0, 1, 2, 3 and healthy volunteers, the ADC values were (1.13±0.25, 1.11±0.17, 1.05±0.24, 0.89±0.04 and 1.00±0.21)×10-3mm2/s, D values were (0.92±0.13, 0.90±0.19, 0.90±0.03, 0.67±0.03, 0.81±0.03)×10-3mm2/s, f values were 0.20±0.04, 0.18±0.02, 0.15±0.01, 0.11±0.01, 0.15±0.06, and D*values were (53.89±28.26, 41.78±16.35, 51.24±18.69, 31.83±18.03, 36.83±16.14)×10-3mm2/s respectively. The ADC, D, f, and D*values of parotid glands in patients with SS at grade 0 were significantly higher than those in healthy volunteers (all P<0.05). Significant differences were observed in the D and f values of parotid glands in patients with SS among different grades (P=0.003,<0.001, respectively). The IVIM parameters (D, f) of parotid glands at early (grades 0-1) and advanced (grades 2-3) stages in patients with SS were significantly higher and lower, respectively, than those in healthy volunteers (all P<0.05). The D and f values inversely correlated with MR nodular grades significantly (r=- 0.297, P=0.019; r=- 0.653, P<0.001, respectively) CONCLUSION: The parotid glands with different MR nodular grades in patients with SS showed different IVIM parameters, reflecting different pathophysiological characteristics of parotid glands at different stages.
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: chuchen19920905@163.com.
authors.forename: Chen
authors.initials: C
authors.lastname: Chu
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: snscorpion@163.com.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Department of Rheumatology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: 13770560567@163.com.
authors.forename: Huayong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: douxin125@126.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Dou
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: lm069393@163.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: liusongnj@126.com.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Rheumatology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: qqt111@hotmail.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Philips Healthcare, Shanghai, 200233, China. Electronic address: Weibo.Chen@philips.com.
authors.forename: Weibo
authors.initials: W
authors.lastname: Chen
authors.affiliation: Philips Healthcare, Hong Kong, China. Electronic address: queenie.chan@philips.com.
authors.forename: Queenie
authors.initials: Q
authors.lastname: Chan
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: hjxueren@126.com.
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Rheumatology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: lysun_nju@163.com.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China. Electronic address: zyzhou@nju.edu.cn.
authors.forename: Zhengyang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D010305:Parotid Diseases / Q000473:pathology*; D010865:Pilot Projects; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012859:Sjogren's Syndrome / Q000473:pathology*; D055815:Young Adult
keywords: Intravoxel incoherent motion; Magnetic resonance; Parotid gland; Sjögren’s syndrome