High-resolution magnetic resonance imaging of triangular fibrocartilage complex lesions in acute wrist trauma: image quality at different field strengths.
OBJECTIVE
The purposes of this study were to assess the diagnostic capacity of a new high-resolution imaging protocol for the wrist and triangular fibrocartilage complex (TFCC) lesions at 3.0 T and to compare it with our established 1.5-T protocol.


METHODS
Twenty-one patients with an acute wrist trauma were examined at a 3.0-T imaging system and agreed to undergo an additional examination at 1.5 T. Magnetic resonance imaging was performed with 1.5-T (standard wrist coil) and 3.0-T (purpose-build phased-array coil) imaging system, using coronal T1-weighted turbo-spin-echo, proton density-weighted fat-saturated, and coronal and axial contrast-enhanced T1-weighted gradient-echo fat-saturated sequences, with reduced voxel size from 0.50 x 0.50 x 3.0 mm (1.5 T) to 0.20 x 0.20 x 1.5 mm (3.0 T). For qualitative analysis, 2 observers assessed in consensus delineation, image quality, and artifacts in anatomical landmarks (cartilage, TFCC, and TFCC lesion) and ranked them on a 5-point scale from 1 (nondiagnostic) to 5 (optimal). For quantitative analysis, measurements of the contrast-to-noise ratio were obtained between disk and surrounding tissue.


RESULTS
All parts of the TFCC and TFCC lesions (n = 14) were seen significantly better at 3.0 T (mean [SD], 4.6 [0.5] vs 2.6 [1.2], P < 0.0001), with higher ranked overall image quality. In 3 cases, TFCC lesions were seen only at 3.0 T. Proton density-weighted fat-saturated sequence had significantly more artifacts at 3.0 T (2.5 [0.6] vs 1.9 [0.5], P < 0.001) in contrast to T1 sequences. Quantitative evaluation showed significantly higher contrast-to-noise ratio for 3.0 T (5.0 [1.1] vs 3.9 [0.9], P < 0.0001).


CONCLUSIONS
Depiction of anatomy and pathology of the TFCC benefits significantly from 3.0-T imaging when higher signal-to-noise ratio is invested into improved spatial resolution. Especially small lesions of the disk were detected only or better at 3.0 T.
Stehling
Christoph
C
Department of Clinical Radiology, University of Muenster, Münster, Germany. cstehling@uni-muenster.de
Bachmann
Rainald
R
Langer
Martin
M
Nassenstein
Isabelle
I
Heindel
Walter
W
Vieth
Volker
V
D000208:Acute Disease; D003287:Contrast Media; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D015588:Observer Variation; D010865:Pilot Projects; D051478:Triangular Fibrocartilage / Q000473:pathology*; D014954:Wrist Injuries / Q000473:pathology*
D003287:Contrast Media