Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose:
EOS® is a new osteoarticular imaging modality with significantly lower radiation than conventional computed radiography (CR). However, the diagnostic performance of this 2D biplanar imaging technique has yet to be evaluated and compared to CR. Diagnosis and follow-up of spondyloarthritis (SpA) by assessment of sacroiliitis and spinal ankylosis with the mSASSS is usually assessed by CR. We aimed to establish whether EOS could replace CR for SpA diagnosis and follow-up by: 1) validating the diagnosis of sacroiliitis by EOS versus by pelvic CR. 2) validating the analysis of spine involvement in SpA by EOS vs spine CR.
Methods: Study design: Observational, single center, prospective. Patients: 108 patients were included. 56 had a definite diagnosis of axial SpA (according to the rheumatologist). In order to assess the specificity of the imaging, 52 control patients with chronic mechanical back pain were enrolled. Data collected: demographic and disease data. All patients underwent CR and 2D EOS imaging of the pelvis and entire spine. Radiologic analysis: a) The diagnostic capacity of 2D EOS and CR for detection of sacroiliitis between SpA patients and controls was compared by calculation of sensitivity (Se) and specificity (Spe). b) Agreement between modalities was compared for spinal involvement scored with the mSASSS, and for sacroiliitis scored according to the modified New York (mNY) score. c) Subjective global visibility of anatomical structures and lesions on both modalities was assessed by the readers and compared by visual numeral scale (in a 0-10 scale). Two independent readers performed a blinded reading of both imaging modalities. Statistical analysis: Weighted kappa and ICC were used with a defined non-inferiority limit of 0.7.
Results: Demographics: Among SpA patients: Mean (SD) age was 48.4 (±15.1) years, sex ratio was 42 males/14 women. Disease duration was 16.6 (±11.2) years. Fifty-two (92.9%) patients fulfilled the ASAS criteria. Thirty-seven (74.0%, n=50) patients presented with sacroiliitis according to mNY criteria according to medical files. Radiologic analysis: a) sacroiliitis diagnostic capacity: Sen was 0.62 and 0.63 for EOS and CR, respectively, and Spec was 0.84 for both modalities; b) agreement between the 2 imaging modalities: Spine: ICC (95%CI) agreement between EOS and CR by mSASSS scoring was 0.82 (0.71-0.89). Sacroiliac joints: Kappa (95% CI) agreement for the scoring of sacroiliac joint abnormalities according to the mNY criteria between EOS and CR was 0.5 (0.26-0.74); c) Subjective global visibility of EOS in SpA: was evaluated at 7.2 (±0.8), vs. 8.2 (±0.9) for CR (p<0.0001).
Conclusion: This study suggests that EOS 2D imaging could replace CR for the diagnosis and follow-up of ankylosis of the spine in SpA, since radiation exposure is much lower However its place in the diagnosis of sacroiliitis remains unclear. Forward studies using MRI as a discriminative modality are ongoing.
Disclosure:
A. Moltó,
None;
V. Freire,
None;
A. Feydy,
None;
S. Paternotte,
None;
W. P. Maksymowych,
None;
M. Benhamou,
None;
F. Rannou,
None;
M. Dougados,
None;
L. Gossec,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/eos-imaging-could-replace-conventional-computed-radiography-for-ankylosis-assessment-in-axial-spondyloarthritis/