RESEARCH - Detection of bone erosions in RA wrist joints with MRI, CT and radiography

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Arthritis Research & Therapy 2008, 10:R25doi:10.1186/ar2378

Published: 28 February 2008

Research article

Detection of bone erosions in rheumatoid arthritis wrist joints with

magnetic resonance imaging, computed tomography and radiography

Uffe Møller Døhn , Bo J Ejbjerg , Hasselquist , Eva Narvestad ,

Jakob Møller , Henrik S Thomsen and Mikkel Østergaard

Arthritis Research & Therapy 2008, 10:R25doi:10.1186/ar2378

Background

The objectives of this study were, with multidetector computed

tomography (CT) as the reference method, to determine the performance

of magnetic resonance imaging (MRI) and radiography for the detection

of bone erosions in rheumatoid arthritis (RA) wrist bones, and to test

if measuring volumes of erosions on CT and MRI is reproducible and

correlating to semi-quantitative assessments (scores) of erosions on

CT, MRI and radiography.

Methods

Seventeen patients with RA and four healthy control individuals

underwent CT, MRI and radiography of one wrist, performed on the same

day. CT was performed on a Philips Mx8000IDT unit (voxel-size 0.4 x

0.4 x 1 mm) and MRI was performed on a Philips Panorama 0.6T unit

(voxel-size 0.4 x 0.4 x 0.4 mm). Images were evaluated separately for

erosions in all wrist bones and scored according to the principles of

the OMERACT RAMRIS (CT and MRI) and Sharp/van der Heijde (radiographs)

scoring methods. Measurements of erosion volumes of all erosions were

done twice with a one week interval.

Results

With CT as the reference method, the overall sensitivity, specificity

and accuracy (concordance) of MRI for detecting erosions were 61%, 93%

and 77%, respectively, while 24%, 99% and 63% for radiography. The

intramodality agreements when measuring erosion volumes were high for

both CT and MRI (Spearman correlation coefficients 0.92 and 0.90 (both

p<0.01), respectively). Correlations between volumes and scores of

individual erosions were 0.96 for CT and 0.99 for MRI, while 0.83 (CT)

and 0.80 (MRI) for personsa total erosion volume and total score (all

p<0.01).

Conclusion

With CT as the reference method, MRI showed moderate sensitivity and

good specificity and accuracy for detection of erosions in RA and

healthy wrist bones, while radiography showed very low sensitivity.

The tested volumetric method was highly reproducible and correlated to

scores of erosions.

http://arthritis-research.com/content/10/1/R25/abstract

Full text: http://arthritis-research.com/content/pdf/ar2378.pdf

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