MR imaging in graft-dependent recurrent hyperparathyroidism after parathyroidectomy and autotransplantation.

The purpose of this study was to compare the value of MR imaging versus sonography in the detection of hyperfunctioning transplanted parathyroid tissue. After parathyroidectomy and autotransplantation of parathyroid tissue to the forearm, 14 patients were examined with sonography and MR imaging. Five of these patients had recurrent hyperparathyroidism. In three of these five, sonography found one echolucent nodule. MR imaging in all three patients detected, in addition to this nodule, other small nodules of hyperplastic parathyroid tissue, which were confirmed intraoperatively. In the other two patients, sonographic and MR imaging findings were negative. Further investigations showed that both patients had a fifth parathyroid gland. In the patients without recurrent hyperparathyroidism, sonography showed scar tissue only, whereas MR imaging found some tiny, contrast-enhancing structures in two patients, probably autograft material. MR imaging seems to be more sensitive than sonography in detecting hyperfunctioning autotransplanted parathyroid tissue.