Evaluation of Different Findings in Simultaneous CTA and MRA of the Wrist

Presentation Format: Oral presentation.

Purpose or Learning Objective: Three-compartment arthrography combined with either computed tomography (CTA) or magnetic resonance imaging (MRA) is the imaging reference standard in the assessment of injuries of the intrinsic interosseous ligaments (scapholunate ligament [SLL] and lunotriquetral ligament [LTL]) and the triangular fibrocartilage complex (TFCC). According to the literature, neither of the methods is clearly superior. Based on 32 patients who underwent both CTA and MRA, strengths and weaknesses of each method are highlighted.

Methods or Background: A total of 32 patients underwent a three-compartment CTA as well as MRA at 3 T. Two musculoskeletal radiologists analyzed the SLL, LTL, TFCC, and the articular cartilage at the radiocarpal and midcarpal compartments. In CTA and MRA analyses, both two-dimensional and three-dimensional data sets were available to the radiologists.

Results or Findings: In 17 of 32 patients (53%), identical results were reported for the evaluated regions on CTA and MRA. Different results were seen for the following entities: In 7 of 32 patients (22%), areas of bone marrow edema were detected on MRA in the absence of fracture lines, ligament tears, or cartilage damage. Eight of 32 patients (25%) showed tenosynovitis on MRA only. In 5 of 32 patients (16%), intact but thickened dorsal SLL segments were seen on CT and MRA; however, edema or hemorrhage could be detected only on MRI (100%) on the basis of hyperintense signal intensity. Four patients had partial tears of the foveal lamina of the TFCC on CTA, but only two of four partial tears (50%) were detectable with MRA. Ten patients showed degenerative changes of the articular disk (TFCC); however, in 3 of 10 of these patients (30%), the disks appeared significantly more thinned on CTA compared with MRA. In two of seven of the previously mentioned patients with bone marrow edema (29%), fracture lines were only depictable on CTA. Finally, in two of five patients (40%) with chondropathia, the height of the articular cartilage was more decreased on CTA when compared with MRA.

Conclusion: At the wrist, MRA is advantageous over CTA in detecting soft tissue injuries and bone marrow edema of different etiologies. In contrast, CTA is more accurate in visualizing discrete lesions of the TFCC and cartilage height in chondropathy due to its better spatial resolution. Combined CTA and MRA clearly provides the most accurate results at the wrist.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
03 June 2021