MR imaging of the wrist in rheumatoid arthritis using gadobenate dimeglumine.
OBJECTIVE
To determine the dosage of gadobenate dimeglumine (Gd-BOPTA) necessary for MRI of rheumatoid arthritis of the wrist.


METHODS
Seven wrists inflamed with rheumatoid arthritis were imaged using a dedicated 0.2-T MR unit. Four cumulative dosages of 0.0125, 0.025, 0.05 and 0.1 mmol/kg body weight (BW) Gd-BOPTA were tested. Three-dimensional T1-weighted gradient-recalled echo sequences (GRE; TR: 100 ms, TE: 18 ms, flip angle 90 degrees , 4:55 min) were acquired prior to an intravenous injection and after each additional dosage of Gd-BOPTA. Relative enhancement, signal-difference-to-noise ratios (SDNRs) and the size of the inflamed tissue were quantified. Three radiologists independently evaluated the image quality, the size and the contrast of the enhancing tissue.


RESULTS
The readers agreed on a dose of 0.05 mmol/kg BW as satisfactory for the evaluation of the size of the inflammatory tissue and for determination of bone involvement (kappa = 0.9, P < 0.001). Highly inflammatory pannus was depicted with adequate image contrast using 0.025 mmol/kg BW Gd-BOPTA. According to the SDNR and relative enhancement findings, a dose of 0.05 mmol/kg BW suffices for both off-center and centered regions of tissue inflammation (t-test, P < 0.05).


CONCLUSIONS
Gadolinium-BOPTA is an alternative contrast agent for MRI of rheumatoid disease. This study shows that a dose of 0.05 mmol/kg BW suffices at low field strength.
Bonél
H M
HM
Institute for Clinical Radiology, Ludwig Maximilians University, Munich-Grosshadern, Munich, Germany.
Schneider
P
P
Seemann
M D
MD
Huegli
R
R
Srivastav
S
S
Lodemann
K P
KP
Reiser
M
M
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000175:diagnosis*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine / Q000008:administration & dosage / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage; D014955:Wrist Joint / Q000473:pathology*
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine