[The MR tomography of avascular necrosis of bone: the primary findings and the follow-up observations after core decompression].

PURPOSE: To assess the signal changes of avascular bone necrosis after core decompression.

PATIENTS AND

METHODS

17 patients with avascular epiphyseal necrosis were examined by MRI using T1-weighted spin echo sequences before and after gadopentetate dimeglumine application, T2-weighted spin echo sequences and in some patients with fat-saturated 2D gradient echo sequences up to 22 months after core decompression.

RESULTS

All patients but one recovered from symptoms after core decompression. Although the signal morphology of the necrotic area remained unchanged in the majority of the cases, a decrease of the joint effusion was observed as well as an ongoing signal increase after gadopentetate dimeglumine application. The last examinations displayed similar signal characteristics as on the preoperative scans; however, a reduction of the necrotic zone became evident.

CONCLUSIONS

The decrease of joint effusion indicates successful core decompression, while a persistent signal increase after gadopentetate dimeglumine application reflects the viability of the necrotic area as well as an ongoing healing process.