MRI of the knee in rheumatoid arthritis: Gd-DTPA perfusion dynamics.
OBJECTIVE
Seventeen knees in 13 patients with rheumatoid arthritis (RA) were studied with MRI to clarify the dynamics of Gd-DTPA administered intravenously and to determine an optimal imaging time.


METHODS
Dynamic gradient recalled echo imaging with bolus intravenous injection of Gd-DTPA was performed following unenhanced T1- and T2-weighted SE imaging. Late-phase SE or serial gradient recalled echo images were obtained following dynamic study.


RESULTS
There was rapid enhancement of synovium with maximal enhancement ratio of 96-499% (mean 214 +/- 111%) with Tmax ranging from 120 to 660 s (mean 253 s). The synovial enhancement persisted over 80% of the peak enhancement for 6-27 min (average 12 min) with eventual enhancement of joint effusion from the periphery to the center beginning at 6 min to 8 min, 20 s after contrast medium injection. Complete enhancement of joint effusion was noted in four joints at 24-86 min.


CONCLUSIONS
We conclude that enhancement of synovium in patients with RA is a time-dependent phenomenon, and an optimal imaging time would be within 5 min following contrast medium administration.
Department of Radiology, Dokkyo University School of Medicine, Tochigi-ken, Japan.
M
M
Yamato
K
K
Tamai
T
T
Yamaguchi
W
W
Ohno
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009942:Organometallic Compounds; D004369:Pentetic Acid; D013583:Synovial Membrane / Q000473:pathology
D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D019786:Gadolinium DTPA