Monitoring ankylosing spondylitis therapy by dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging.
OBJECTIVE
The effects of different therapies on enthesitis/osteitis in active ankylosing spondylitis (AS) were evaluated by magnetic resonance imaging (MRI). The aim was to assess the role of quantitative MRI in the evaluation of AS treatment efficacy.


METHODS
Thirty patients with active spondylitis or bilateral sacroiliitis were selected and followed up for 1 year. Ten of the patients were treated only with non-steroidal anti-inflammatory drugs, 10 patients additionally received at baseline an intravenous pulse of glucocorticoids and 10 patients were treated with regular infusions of infliximab. Disease activity was measured according to clinical instruments and laboratory tests. For each patient, one selected inflamed lesion was followed from baseline through control visits quantitatively by diffusion-weighted imaging (DWI) measuring the apparent diffusion coefficient (ADC) and by dynamic contrast-enhanced imaging (DCEI) with evaluation of the enhancement factor (f(enh)) and enhancement gradient (g(enh)).


RESULTS
Clinical and quantitative MRI parameters diminished significantly with regression of the inflammatory activity. The improvement in AS was most pronounced in patients treated with infliximab; after 12 months the ADC diminished from an average of 1.31 to 0.88 x 10(-3) mm(2)/s, f(enh) from 1.85 to 0.60, and g(enh) from 3.09 to 1.40 %/s.


CONCLUSIONS
Diffusion-weighted imaging and DCEI were shown to be effective in quantifying changes in inflammation in skeletal lesions during the treatment of AS, and could therefore be convenient for assessing treatment efficacy. To the best of our knowledge this is the first time DWI was used to evaluate the activity of skeletal inflammation in rheumatic diseases such as AS.
Gaspersic
Natasa
N
Department of Rheumatology, University Medical Centre, Ljubljana, Slovenia. ngaspersic@yahoo.com
Sersa
Igor
I
Jevtic
Vladimir
V
Tomsic
Matija
M
Praprotnik
Sonja
S
D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D003287:Contrast Media / Q000008:administration & dosage*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007249:Inflammation / Q000175:diagnosis; D000069285:Infliximab; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013131:Spine / Q000473:pathology; D013167:Spondylitis, Ankylosing / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
D000893:Anti-Inflammatory Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000911:Antibodies, Monoclonal; D003287:Contrast Media; D005938:Glucocorticoids; D000069285:Infliximab; D019786:Gadolinium DTPA