‹ Back to all protocols

Parathyroid Scan (Tc-99m Sestamibi)

NM+ ContrastHead & Neck

Indications

Localization of parathyroid adenoma in primary hyperparathyroidism
Preoperative localization before minimally invasive parathyroidectomy
Persistent/recurrent hyperparathyroidism
Ectopic parathyroid tissue (mediastinum)

Patient prep

No specific fasting required
Remove neck jewelry/metal
No iodine restriction needed (unlike thyroid radioiodine)

Contrast

AgentTc-99m sestamibi (dual-phase) +/- Tc-99m pertechnetate or I-123 for dual-isotope subtraction

RouteIV

DoseTc-99m sestamibi 20-25 mCi (740-925 MBq)

TimingDual-phase: early 10-15 min, delayed 1.5-3 h (adenoma retains tracer)

Technique

LEHR or pinhole collimator, 140 keV
Dual-phase protocol: early and delayed planar of neck/chest
SPECT or SPECT/CT improves localization (depth, ectopic sites)
Dual-isotope subtraction (sestamibi minus pertechnetate/I-123 thyroid image) alternative technique

Series / Sequences

#	Series / Sequence	Plane	Notes
1	Early phase	Anterior neck/chest	10-15 min post-injection; thyroid + parathyroid uptake
2	Delayed phase	Anterior neck/chest	1.5-3 h; thyroid washes out, adenoma retains
3	SPECT/CT	Axial/multiplanar	3D localization, ectopic/mediastinal glands

Key points

Parathyroid adenomas retain sestamibi longer than thyroid on delayed imaging
SPECT/CT markedly improves anatomic localization and detection of ectopic glands
Small or hyperplastic glands may be missed; correlate with ultrasound and labs
Coexisting thyroid nodules can cause false positives

References

• SNMMI/EANM Practice Guideline for Parathyroid Scintigraphy
• ACR-SPR-SNMMI Practice Parameter for Parathyroid Scintigraphy
• Radiopaedia: Parathyroid scintigraphy link

Source: Researched — verify against your institution

‹ PreviousSialogram (Salivary Gland Ductogram)Next ›Thyroid Cancer I-131 Therapy and Post-Therapy Scan

Reference template — verify and adapt to your scanner, vendor and institution before clinical use. Not a substitute for clinical judgment.