Kay-Geert A. Hermann MD, Presenter: Nothing to Disclose

Robert B. M. Landewé MD,PhD, Abstract Co-Author: Nothing to Disclose

Jürgen Braun MD,PhD, Abstract Co-Author: Nothing to Disclose

Désirée M. F. M. van der Heijde MD,PhD, Abstract Co-Author: Nothing to Disclose

Depiction of inflammatory lesions by magnetic resonance imaging (MRI) in ankylosing spondylitis (AS) is possible both by short tau inversion recovery (STIR) imaging as well as by gadolinium-enhanced T1-weighted imaging with fat saturation (T1/Gd). Aim of this prospective study was to investigate whether gadolinium-enhanced sequences add relevant information compared to STIR imaging alone in the detection of active spinal lesions.

MRI of the spine was performed in 48 patients with AS who participated in a clinical trial with TNF-blocking drugs, by STIR and T1/Gd at baseline and after 6 months. Images were evaluated separately for the two techniques by two readers blinded for true time sequence and treatment. The ASspiMRI-a scoring method (Braun J, et al. Arthritis Rheum 2003; 48:1126-1136.) was used, in which 23 vertebral units are graded for inflammation and active erosions from 0 to 6 (total score 0 to 138).

Mean scorings of both techniques within readers were in the same range (reader 1: STIR 7.8, T1/Gd 7.7; reader 2: STIR 4.4, T1/Gd 4.7). Intraclass correlation coefficients comparing STIR and T1/Gd where high both for status scores (reader 1: 0.88; reader 2: 0.90) and change scores (reader 1: 0.88; reader 2: 0.88). Bland & Altman analysis showed for both sequences homogeneous interreader variability along the entire spectrum of scorings, both for status and change. Smallest detectable changes for status scores were 6.2 for STIR and 6.7 for T1/Gd, and for change scores 6.5 and 6.3, respectively. Standardized response means were comparable for both methods (range: 0.80 – 1.09).

Both STIR and T1/Gd sequences measure inflammation of the spine, as well as change of inflammation, with a high level of agreement. For future clinical randomized trials with MRI of the spine as outcome parameter it could be considered to use STIR as solely imaging technique.

Hermann, K, Landewé, R, Braun, J, van der Heijde, D, Magnetic Resonance Imaging of the Spine in Ankylosing Spondylitis Clinical Trials: Is Paramagnetic Contrast Medium Necessary?.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4405758.html