Postoperative parathyroid high-frequency sonography: evaluation of persistent or recurrent hyperparathyroidism.

Sixty consecutive postoperative patients with recurrent or persistent hyperparathyroidism were scanned before reoperation using high-frequency (10 MHz) real-time sonography. The sonograms were interpreted prospectively, and the results correlated with subsequent surgical findings to determine the diagnostic accuracy of this technique in the localization of enlarged parathyroid glands. A total of 59 abnormal glands were found in 51 patients at operation: 45 in the neck and 14 in the mediastinum. Sonography identified 37 of the 45 cervical glands for a sensitivity of 82% in the neck. The mediastinum cannot be evaluated by sonography due to the bony thoracic cage, although if the mediastinal glands are included, the overall sensitivity was 63%. In the 14 patients with negative neck explorations but positive mediastinal explorations, sonography was negative in 12 patients, but false-positives were suspected in two patients, yielding a specificity of 86% in the neck. High-frequency sonography is a sensitive, rapid, and noninvasive technique for localizing enlarged cervical parathyroid glands in patients with recurrent or persistent hyperparathyroidism.