[Magnetic resonance arthrography in chronic wrist pain]

To investigate the clinical role of Magnetic Resonance Arthrography (MRA) of the wrist in subjects with chronic pain.

Thirty-five patients complaining of wrist pain for more 6 months were submitted to MRI and MRA. All patients received an intra-articular (monocompartment radiocarpal joint) injection of 2-10 mL of a 10 mmol saline solution of Gd-DPTA. Two radiologists independently evaluated the conspicuity of the intrinsic intercarpal ligaments and of the triangular fibrocartilage complex and expressed it on a 3-grade semiquantitative scale. On MRI images, complete visualization of the two structures was graded as 0, partial visualization as 1 and no visualization as 2. On MRA images, no contrast agent passage through the ligament or the complex was graded as 0, minimal passage as 1 and complete passage as 2. Sixteen patients had surgical confirmation (arthroscopy in 10 and open surgery in 6 patients).

On MRI images the scapholunate ligament was completely visualized in 7 patients (21%) and partially or not visualized in 28 patients (89%). MRA images showed an intact ligament in 15 cases (44%) and a partial or total tear in 20 cases (48% and 8% respectively, 56% in all). On MRI images the luno-pyramidal ligament was completely visualized in 6 patients (18%) and partially or not visualized in 29 cases (82%). On MRA images the luno-pyramidal ligament was intact in 21 cases (58%) and had a partial or total tear in 14 cases (27% and 15% respectively, 42% in all). On MRI images the triangular fibrocartilage complex was normal in 27 cases (76%) and it was only partially visualized in 8 cases (24%). On MRA images the triangular fibrocartilage complex was normal in 13 cases (37%) and had a partial injury in 22 cases (63%). There were no severe side-effects to contrast agent injection, nor severe complications. The overall diagnostic accuracy rates of MRI and MRA were 40% and 81% respectively, with sensitivity and specificity of 63% and 39% (MRI) and of 82% and 79% (MRA).

Compared with MRI, MRA can be considered a useful tool for the visualization of interosseous carpal ligaments and of the triangular fibrocartilage complex. MRA also helps detect injuries in these structures.