Improved preoperative planning for directed parathyroidectomy with 4-dimensional computed tomography

Background: Four-dimensional computed tomography (4D-CT) provides both functional and highly detailed anatomic information about parathyroid tumors. The purpose of this study was to compare 4D-CT with sestamibi imaging and ultrasonography as methods for the accurate preoperative localization of hyperfunctioning parathyroid glands before parathyroidectomy. Methods: A study of 75 patients with primary hyperparathyroidism was performed at a tertiary-care institution. Sestamibi imaging, ultrasonography, and 4D-CT were performed on each patient preoperatively. Results of the imaging studies were compared with operative findings, pathologic data, and biochemical measurements to assess the sensitivity and specificity of each of the imaging modalities. Results: 4D-CT demonstrated improved sensitivity (88%) over sestamibi imaging (65%) and ultrasonography (57%), when the imaging studies were used to localize (lateralize) hyperfunctioning parathyroid glands to 1 side of the neck. Moreover, when used to localize parathyroid tumors to the correct quadrant of the neck (ie, right inferior, right superior, left inferior, or left superior), the sensitivity of 4D-CT (70%) was significantly higher than sestamibi imaging (33%) and ultrasonography (29%). Conclusion: 4D-CT provides significantly greater sensitivity than sestamibi imaging and ultrasonography for precise (quadrant) localization of hyperfunctioning parathyroid glands. This allows improved preoperative planning, particularly for the case of reoperation. In addition to the data that are provided, we present a novel classification scheme for use in parathyroid localization.