Study of the Ultrasound Appearance of the Normal Parathyroid Using an Intraoperative Procedure

Objectives This study was designed to confirm the echogenicity of normal parathyroid glands using intraoperative ultrasound (US). Methods Between October 2015 and January 2016, normal parathyroid glands were examined with an intraoperative US transducer during thyroidectomy procedures in 13 patients with thyroid disease. According to the findings from intraoperative US, routine percutaneous US of normal parathyroid glands was performed in a group of adults. On the basis of previous information on normal parathyroid echogenicity, a series of parathyroid diseases that were proved by surgery and histopathologic analyses were retrospectively reviewed. The presence of residual normal parathyroid in the lesion on US imaging, which was defined as the residual parathyroid sign in this study, was reviewed and correlated with histopathologic results. Results In the intraoperative US group, 23 parathyroid glands were scanned intraoperatively, and 21 (91.3%) were hyperechoic, homogeneous in texture, and oval. In the routine percutaneous US group, 106 parathyroid glands were found in total, and 96 (90.5%) of the glands had hyperechoic and homogeneous echogenicity, with 75 (70.8%) being oval. In the review of parathyroid diseases, 33 parathyroid glands in 30 cases were reviewed, with a positive residual parathyroid sign in 7 (21.2%) parathyroid glands, presenting with a hyperechoic rim in the margin, and 4 of them (12.1%) were confirmed by histopathologic results. Conclusions The normal parathyroid had hyperechoic echogenicity on both intraoperative and percutaneous US imaging. Residual tissue of parathyroid glands can also be observed in some parathyroid abnormalities with an echogenic appearance on US imaging and confirmed by histopathologic results.