PT  - JOURNAL ARTICLE
AU  - Torsten Diekhoff
AU  - Kay-Geert A Hermann
AU  - Juliane Greese
AU  - Carsten Schwenke
AU  - Denis Poddubnyy
AU  - Bernd Hamm
AU  - Joachim Sieper
TI  - Comparison of MRI with radiography for detecting structural lesions of the sacroiliac joint using CT as standard of reference: results from the SIMACT study
AID  - 10.1136/annrheumdis-2016-210640
DP  - 2017 Sep 01
TA  - Annals of the Rheumatic Diseases
PG  - 1502--1508
VI  - 76
IP  - 9
4099  - http://ard.bmj.com/content/76/9/1502.short
4100  - http://ard.bmj.com/content/76/9/1502.full
SO  - Ann Rheum Dis2017 Sep 01; 76
AB  - Objective Radiographs of sacroiliac (SI) joints are used for the detection of structural damage in patients with axial spondyloarthritis (axSpA), but are often difficult to interpret. Here, we address the question how the T1-weighted MRI (T1w MRI) sequence compares with radiography for SI joints’ structural lesions using low-dose CT as the standard of reference.Methods Radiographs, T1w MRI and low-dose CT of the SI joints from 110 patients (mean age 36.1 (19–57) years, 52% males and 48% females; 53% with axSpA, 21 non-radiographic axSpA and 32% radiographic axSpA, 47% with non-SpA) referred to the rheumatologist because of unclear chronic back pain, but possible axSpA, were scored for structural lesions (erosions, sclerosis, joint space changes and an overall impression of positivity).Results Using low-dose CT as the standard of reference, T1w MRI showed markedly better sensitivity with significantly more correct imaging findings compared with radiography for erosions (79% vs 42%; p=0.002), joint space changes (75% vs 41%; p=0.002) and overall positivity (85% vs 48%; p=0.001), respectively, while there were no differences between X-rays and MRI-T1 sequence regarding specificity (>80% for all scores). Only for sclerosis, MRI-T1 was inferior to radiography (sensitivity 30% vs 70%, respectively), however, not statistically significant (p=0.663).Conclusions T1w MRI was superior to radiography in the detection of structural lesion of the SI joints in patients with axSpA. Future studies should focus on finding an agreement on the definition of MRI-T1 positivity.