title: Role of single photon emission computed tomography/computed tomography in localization of ectopic parathyroid adenoma: a pictorial case series and review of the current literature.
abstract: The parathyroid glands are located posterior to the upper and lower poles of the thyroid and are derived from the third and fourth pharyngeal pouches. Usually there are only 2 superior glands, whereas only 40% of patients have their inferior glands located near the inferior thyroid poles. Ectopic locations include the carotid sheath, anterior mediastinum, retropharynx, or intrathyroidal locations. Single photon emission computed tomography/computed tomography (SPECT/CT) offers the advantage of combining function and anatomy for exact localization of ectopic parathyroid adenomas. In this pictorial review, we present 4 cases of hyperparathyroidism caused by ectopic parathyroid adenomas and review the literature on the additional value of their localization with SPECT/CT. Combined SPECT/CT scanners permit more reliable localization of ectopic adenomas. The additional information can aid in exact preoperative localization. In one study of 16 patients, SPECT/CT identified 39% more lesions compared with SPECT imaging alone. In other comparisons of planar, SPECT and SPECT/CT imaging modalities, SPECT/CT permitted the highest reader confidence in localization, especially for mediastinal adenomas. Larger studies are needed to establish the role and cost-effectiveness of SPECT/CT.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts 02115, USA. kakram@bidmc.harvard.edu
authors.forename: Kamran
authors.initials: K
authors.lastname: Akram
authors.forename: John Anthony
authors.initials: JA
authors.lastname: Parker
authors.forename: Kevin
authors.initials: K
authors.lastname: Donohoe
authors.forename: Gerald
authors.initials: G
authors.lastname: Kolodny
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed