[Direct CT-arthrography versus direct MR-arthrography in chronic shoulder instability: comparison of modalities after the introduction of multidetector-CT technology].
OBJECTIVE
To evaluate the diagnostic accuracy of direct multidetector CT arthrography (CTA) and direct MR arthrography (MRA) in patients suffering from chronic shoulder instability.


METHODS
Twenty-nine patients suffering from chronic shoulder instability were included into a prospective study. In all cases, the indication for direct CTA and arthroscopy was set by the orthopedic surgeon. Prior to the imaging procedures, 10 to 20 ml of a special combination of contrast media (including saline, Isovist(R) and Magnevist(R) in a relation of 125 : 125 : 1) was injected into the joint under sterile conditions. First, CTA was performed with a multidetector CT, with images reconstructed in the axial, semi-coronal and semi-sagittal planes. Thereafter, MRA was performed. Axial images were obtained using a T1-weighted, fat-saturated spin echo sequence and semi-coronal images using a T1-weighted FLASH-3D GRE sequence. The results of CTA and MTA were compared with results obtained from arthroscopy or arthrotomy.


RESULTS
MRA was superior to CTA in the detection of labral lesions. The sensitivity of MRA was 96 % and the specificity 96 %, compared to a sensitivity of 76 % (p < 0.05) and specificity of 92 % for CTA. Both methods showed the same effectiveness concerning the assessment of capsule distension (sensitivity for both techniques: 91 %).


CONCLUSIONS
MRA seems to be superior to CTA in the diagnostic workup of chronic shoulder instability even when using a multidetector CT technique.
Bitzer
M
M
Abteilung Radiologische Diagnostik, Universität Tübingen. radiologie@zolleernalb-klinikum.de
Nasko
M
M
Krackhardt
T
T
Schick
F
F
Schöber
W
W
Wiskirchen
J
J
Morgalla
M
M
Weise
K
K
Claussen
C
C
D000293:Adolescent; D000328:Adult; D001175:Arthrography / Q000379:methods*; D002908:Chronic Disease; D003287:Contrast Media; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012540:Scapula / Q000000981:diagnostic imaging / Q000473:pathology; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed
D003287:Contrast Media