Vol.20 No.6

Original Article

Comparison of low-field dedicated extremity magnetic resonance imaging with articular ultrasonography in patients with rheumatoid arthritis

Authors

Masanobu Horikoshi1 , Takeshi Suzuki1 , Makoto Sugihara1 , Yuya Kondo1 , Hiroto Tsuboi1 , Takeaki Uehara2 , Maasa Hama2 , Kaoru Takase3 , Shigeru Ohno3 , Yoshiaki Ishigatsubo2 , Yuri Yoshida4 , Akira Sagawa4, Kei Ikeda5, Toshiyuki Ota6, Isao Matsumoto1, Satoshi Ito1, Takayuki Sumida1

  • Doctoral Program in Clinical Sciences, Division of Clinical Immunology, Graduate School of Comprehensive Human Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba Ibaraki, 305-8575, Japan
  • Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
  • Center for Rheumatic Diseases, Yokohama City University Medical Center, Yokohama, Japan
  • Sagawa Akira Rheumatology Clinic, Sapporo, Japan
  • Department of Allergy and Clinical Immunology, Chiba University, Chiba, Japan
  • Department of Laboratory and Transfusion Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
Received:

1 March 2010

Accepted:

7 May 2010

Published online:

4 June 2010

Full Text

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Abstract

To compare magnetic resonance imaging (MRI) and ultrasonography (US) in the detection of joint inflammation of rheumatoid arthritis (RA), 6 patients with RA were examined by US and low-field 0.3-T nonenhanced dedicated extremity MRI (compacTscan). All patients were females, with mean age of 50.2 years, mean disease duration of 13.5 years, and mean disease activity score (DAS)28-CRP of 1.78. Each patient was treated with either infliximab, etanercept, adalimumab, or tocilizumab. Intercarpal joints, radioulnar joints, second through fifth proximal interphalangeal (PIP) joints, and first through fifth metacarpophalangeal (MCP) joints (a total of 132 joints, 22 joints in each patient) were assessed by MRI for presence of joint inflammation. A total of 156 joints (24 first interphalangeal and radiocarpal joints plus the above 132 joints), were assessed by grayscale US (GS-US) and power Doppler US (PD-US) for presence of joint inflammation by two trained ultrasonographers. We assessed correlations between joint inflammations on MRI and GS-US/PD-US, and also interobserver correlation between the two ultrasonographers by calculating intraclass correlation coefficients (ICC). Synovial hypertrophy and/or synovial fluid was detected in 74/156 joints on GS-US, and synovitis was detected in 10/156 joints on PD-US and in 38/132 joints on MRI. Using PD-US as a reference, sensitivity of MRI in detection of synovitis was 80%. Using MRI as a reference, sensitivity of PD-US was 21%. Specificity of PD-US was higher than that of MRI. Overall agreement between GS-US and MRI and between PD-US and MRI was 0.56 and 0.76, respectively, suggesting that results of PD-US are close to those of MRI. ICC was 0.545 for GS-US and 0.807 for PD-US, suggesting specificity of PD-US in detecting joint inflammation. Our results show that findings of PD-US correlated with those of MRI. Low-field MRI and PD-US are useful tools for assessment of patients with RA.

Key words

GS-US - MRI - PD-US - Synovitis - Rheumatoid arthritis