Preoperative localization of parathyroid adenomas.

During a 12-month period, 64 patients were operated on for primary hyperparathyroidism. Sixty-one had single adenomas and 3 had double adenomas. Preoperative imaging was used to localize the adenomas. Half of the patients (32 of 64) had magnetic resonance, thallium-201/technetium-99m subtraction scintigraphy, and high-resolution ultrasonography; the other 32 patients had 1 or 2 of the imaging modalities. Sensitivity and specificity of magnetic resonance imaging was 82 percent and 97 percent, respectively; the sensitivity and specificity of the other two modalities was 59 and 98 percent for subtraction scintigraphy and 73 and 98 percent for ultrasonography. The use of preoperative imaging facilitated surgical exploration, reduced operating time, and resulted in an increased number of successful operations. There were no negative explorations in this series as compared with 19 negative explorations (2.6 percent) in our prior experience with 720 operations.