[Comparison of contrast-enhanced low mechanical index (Low MI) sonography and unenhanced B-mode sonography for the differentiation between synovitis and joint effusion in patients with rheumatoid arthritis].
OBJECTIVE
To test whether contrast-enhanced low mechanical index (low MI) sonography is superior to non enhanced B-Mode sonography in differentiating synovitis and joint effusion.


METHODS
In a retrospective study, 22 patients with proven rheumatoid arthritis underwent B-Mode sonography and low-MI sonography of 25 symptomatic joints of the upper and lower limbs. For low-MI sonography, 5 ml Sonovue (Bracco Altana Pharma GmbH, Konstanz) were injected as an intravenous bolus followed by 10 ml of 0.9 % saline solution. Magnetic resonance imaging (MRI) was obtained additionally in 3 joints. With non-enhanced sonography, we diagnosed a synovitis in case of an echogenic and a joint effusion in case of an anechoic mass. With contrast-enhanced sonography, we diagnosed a synovitis in case of enhancement and a joint effusion in the absence of enhancement of the intraarticular mass.


RESULTS
In 13 joints, synovitis and joint effusion were differentiated by both non-enhanced and enhanced sonography. In 12 joints, this differentiation was only possible with contrast-enhanced sonography. In 3 patients diagnosed by sonography as having a synovitis, this diagnosis was proven by MRI.


CONCLUSIONS
Contrast-enhanced low-MI sonography is superior to non-enhanced B-Mode sonography in differentiating synovitis and joint effusion.
Kleffel
T
T
Klinik für Diagnostische Radiologie und Neuroradiologie, Klinikum Augsburg.
Demharter
J
J
Wohlgemuth
W
W
Schalm
J
J
Bohndorf
K
K
Kirchhof
K
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016009:Chi-Square Distribution; D003287:Contrast Media; D003937:Diagnosis, Differential; D005122:Exudates and Transudates / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D012189:Retrospective Studies; D013459:Sulfur Hexafluoride; D013585:Synovitis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride