4D-CT for Detection of Parathyroid Adenomas and Hyperplasia: State of the Art Imaging

Purpose of Review: Radiologic localization of parathyroid lesions is essential for the surgical treatment of primary hyperparathyroidism. In recent years, multiphase parathyroid 4D-CT has evolved from an adjunct imaging technique to a first-line choice for planning parathyroidectomy at some institutions. Here, we review the background, technique, and interpretation of parathyroid 4D-CT. Recent Findings: Compared with the traditional modalities of scintigraphy and ultrasound, CT provides superior sensitivity for localizing parathyroid lesions, and is particularly valuable in the setting of planning remedial surgery and when patients have multi-gland disease (double adenomas or four-gland hyperplasia). A three-phase CT protocol optimizes lesion detection and characterization. A systematic approach to image interpretation and reporting, incorporating the Duke 4D-CT scoring system, enables radiologists to convey relevant information and facilitate successful surgery. Summary: We recommend using a three-phase CT protocol and provide an updated six-step approach to parathyroid CT interpretation and reporting.