Optimizing the MRI protocol of the sacroiliac joints in Spondyloarthritis: which para-axial sequence should be used?
BACKGROUND
To assess the diagnostic value of para-axial T2w-TSE (paT2) and fat-suppressed proton density (paPD-FS) MRI sequences for the evaluation of the sacroiliac joint (SIJ) of patients with axial Spondylarthritis (SpA).


METHODS
One hundred and six patients with clinical findings suggestive of SpA underwent an MR protocol of the SIJ with additional paPD-FS (41 patients) and paT2 (105 patients). Acute (bone marrow oedema [BME], enthesitis, capsulitis, synovitis) and chronic findings (erosions, ankylosis) were assessed by paPD-FS and compared with the gold standard post-contrast sequences, whereas chronic features (because of the lack of fat suppression) were evaluated on paT2 and compared with pcT1.


RESULTS
paPD-FS demonstrated high sensitivity (98.9 %) and specificity (99.1 %) for BME; sensitivity and specificity for synovitis and enthesitis were 100 %; 85.7 % and 100 %, respectively, for capsulitis. paPD-FS and paT2 showed 100 % sensitivity and specificity for ankylosis; for erosions, paT2 demonstrated 85.3 % sensitivity and 100 % specificity, whereas paPD-FS, respectively, 98 % and 100 %.


CONCLUSIONS
PaT2 and paPD-FS provided precious information enabling an accurate interpretation of the heterogeneous findings of SpA. paPD-FS showed good results in detecting acute and chronic lesions and its inclusion in a routine MR examination of the SIJ could increase the diagnostic performance of a pre-contrast protocol.


CONCLUSIONS
Para-axial sequence should be included in a routine MRI protocol for SpA. Acute and chronic findings can be evaluated on para-axial PD-FS. Para-axial PD-FS is superior to para-axial T2-W in SpA.
Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna, Vienna General Hospital, Waehringer Guertel 18-20, Vienna, 1090, Austria.
Chiara
C
Giraudo
Dipartimento di Radiologia e Diagnostica per Immagini, Fondazione Poliambulanza Istituto Ospedaliero, Brescia, Italy.
Silvia
S
Magnaldi
Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna, Vienna General Hospital, Waehringer Guertel 18-20, Vienna, 1090, Austria.
Michael
M
Weber
Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna General Hospital, Waehringer Guertel 18-20, Vienna, 1090, Austria.
Antonia
A
Puchner
Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna, Vienna General Hospital, Waehringer Guertel 18-20, Vienna, 1090, Austria.
Hannes
H
Platzgummer
Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna, Vienna General Hospital, Waehringer Guertel 18-20, Vienna, 1090, Austria.
Franz
F
Kainberger
Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna, Vienna General Hospital, Waehringer Guertel 18-20, Vienna, 1090, Austria. claudia.schueller-weidekamm@meduniwien.ac.at.
Claudia
C
Schueller-Weidekamm
D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012372:ROC Curve; D015203:Reproducibility of Results; D012446:Sacroiliac Joint / Q000473:pathology*; D025241:Spondylarthritis / Q000175:diagnosis*
Acute disease; Chronic disease; MRI; Sacroiliitis; Spondylarthritis