MRI with surface coils for parathyroid tumors: preliminary investigation.

The ability of MRI to detect parathyroid gland enlargement was assessed using 1.5-T systems and surface coil reception. Nine patients with primary hyperparathyroidism were studied before surgical neck exploration. Five-millimeter-thick axial images were obtained from the thyroid cartilage to the sternal notch. Both T1 and T2 contrast-weighted spin-echo sequences were performed in most cases. MRI correctly identified six out of seven parathyroid adenomas. In the false-negative case, T2 contrast-weighted sequences were not performed for technical reasons. In the one case of surgically proven parathyroid hyperplasia, a lesion identified by MRI as a parathyroid adenoma coincided at surgery with the largest of three hyperplastic parathyroid glands. A single case demonstrated a potential pitfall in the search for ectopic parathyroid glands: A large colloid cyst in the posterior portion of the thyroid gland showed signal characteristics indistinguishable from a parathyroid adenoma. The enlarged parathyroid glands were best visualized on T2 contrast-weighted sequences, with the lesions demonstrating greater signal than surrounding tissues.