This consensus statement from the members of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine recommends a standardized method for measuring gastric emptying (GE) by scintigraphy. A low-fat, eggwhite meal with imaging at 0, 1, 2, and 4 h after meal ingestion, as described by a published multicenter protocol, provides standardized information about normal and delayed GE. Adoption of this standardized protocol will resolve the lack of uniformity of testing, add reliability and credibility to the results, and improve the clinical utility of the GE test.

This consensus statement from the members of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine recommends a standardized method for measuring gastric emptying (GE) by scintigraphy. A low-fat, egg-white meal with imaging at 0, 1, 2, and 4 h after meal ingestion, as described by a published multicenter protocol, provides standardized information about normal and delayed GE. Adoption of this standardized protocol will resolve the lack of uniformity of testing, add reliability and credibility to the results, and improve the clinical utility of the GE test.

Various methodologies for 99m Tc-sestamibi parathyroid scintigraphy are in clinical use. There are few direct comparisons between the different methods and even less evidence supporting the superiority of one over another. Some reports suggest that SPECT is superior to planar imaging. The addition of CT to SPECT may further improve parathyroid adenoma localization. The purpose of our investigation was to compare hybrid SPECT/CT, SPECT, and planar imaging and to determine whether dual-phase imaging is advantageous for the 3 methodologies. Methods: Scintigraphy was performed on 110 patients with primary hyperparathyroidism and no prior neck surgery. Of these, 98 had single adenomas and are the subject of this review. Planar imaging and SPECT/CT were performed at 15 min and 2 h after injection. Six image sets (early and delayed planar imaging, SPECT, and SPECT/CT) and combinations of the 2 image sets were reviewed for adenoma localization at 13 possible sites. Each review was scored for location and certainty of focus by 2 reviewer groups. Surgical location served as the standard. Sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, and k-values were determined for each method. Results: The overall k-coefficient (certainty of adenoma focus) between reading groups was 0.68 (95% confidence interval, 0.66-0.70). The highest values were for dualphase studies that included SPECT/CT. Dual-phase planar imaging, SPECT, and SPECT/CT were statistically significantly superior to single-phase early or delayed imaging in sensitivity, area under the curve, and positive predictive value. Neither single-phase nor dual-phase SPECT was statistically superior to dual-phase planar imaging. Early-phase SPECT/CT in combination with any delayed imaging method was superior to dualphase planar imaging or SPECT for sensitivity, area under the curve, and positive predictive value. Conclusion: Early SPECT/ CT in combination with any delayed imaging method was statistically significantly superior to any single-or dual-phase planar or SPECT study for parathyroid adenoma localization. Localization with dual-phase acquisition was more accurate than with singlephase 99m Tc-sestamibi scintigraphy for planar imaging, SPECT, and SPECT/CT.

The clinical diagnosis of primary hyperparathyroidism is based largely on serum laboratory test results, as patients often are asymptomatic. Surgery, often with bilateral exploration of the neck, has been considered the definitive treatment for symptomatic disease. However, given that approximately 90% of cases are due to a single parathyroid adenoma, a better treatment may be the selective surgical excision of the hyperfunctioning parathyroid gland after its preoperative identification and localization at radiologic imaging. Scintigraphy and ultrasonography are the imaging modalities most often used for preoperative localization. Various scintigraphic protocols may be used in the clinical setting: Single-phase dual-isotope subtraction imaging, dual-phase single-isotope imaging, or a combination of the two may be used to obtain planar or tomographic views. Single photon emission computed tomography (SPECT) with the use of technetium-99m ((99m)Tc) sestamibi as the radiotracer, especially when combined with x-ray-based computed tomography (CT), is particularly helpful for preoperative localization: The three-dimensional functional information from SPECT is fused with the anatomic information obtained from CT. In addition, knowledge of the anatomy and embryologic development of the parathyroid glands and the pathophysiology of primary hyperparathyroidism aid in the identification and localization of hyperfunctioning glands.