In this session, Ziad Risheq provides a practical, step-by-step guide to Tc-99m sestamibi (MIBI) parathyroid scintigraphy for localizing hyperfunctioning parathyroid tissue in biochemically proven primary hyperparathyroidism. You’ll learn why MIBI works (mitochondrial-rich oxyphil cells and retention differences vs thyroid), how to run and interpret the two main approaches (dual-phase imaging and dual-tracer subtraction, with SPECT/CT as a localization problem-solver), and what “classic” positive studies look like—including ectopic locations and when to extend the field to the mediastinum. The lecture also highlights key physiologic uptake patterns, patient preparation considerations (motion, metal, iodine/thyroid-related factors for subtraction), and the most important pitfalls that lead to false positives and false negatives.

Learning Objectives

By the end of this lecture, learners will be able to:

• State the clinical indication and role of MIBI parathyroid scintigraphy—recognizing that the diagnosis is biochemical and imaging is performed for localization (including ectopic disease).
• Describe and apply the main protocols (dual-phase and dual-tracer subtraction) and explain when SPECT/CT adds value for confident anatomic localization.
• Interpret studies with a pitfall-aware approach, distinguishing physiologic uptake and artifacts from true parathyroid lesions, and recognizing common causes of false positives (e.g., thyroid nodules, motion) and false negatives (e.g., small lesions, hyperplasia, low-oxyphil/rapid washout lesions, slow thyroid washout).