Single-Photon Scintigraphic Imaging of the Parathyroid Glands: Planar, Tomography (SPECT), and SPECT-CT

The ability to image the parathyroid glands with scintigraphy, and hyperplastic or adenomatous glands in particular, dates back to 1964 when Potchen and Sodee visualized a parathyroid adenoma using Se-75 selenomethionine in a 31-year-old male suffering from painful bone disease [55]. In the ensuing 45 years, imaging of the parathyroid glands evolved to include the administration of 99m-technetium sestamibi (“MIBI”) followed by a planar scintigraphic technique. Today, the investigation of parathyroid function utilizing three-dimensional tomographic techniques has grown due to the increasing availability of cameras able to reconstruct volumetric data into axial, coronal, and sagittal planes. This technique, single-photon emission tomography (SPECT), has allowed for improved reader confidence in the detection of parathyroid disease largely due to the ability to differentiate overlying structures from abnormal parathyroid glands. Likewise, the increasing availability of hybrid cameras which incorporate both SPECT and computed tomography (CT) has engendered a rush to utilize this hybrid technique (SPECT-CT) for parathyroid localization as it allows for anatomic correlations and localizations that are translatable to a surgical approach. This chapter discusses the current literature regarding the use of planar, SPECT, and SPECT-CT in the evaluation of eutopic and ectopic parathyroid disease, primarily in patients with primary hyperparathyroidism.