Bone Scan (Tc-99m MDP)
Whole-body scintigraphy using technetium-99m methylene diphosphonate (or HDP) — sensitive for osseous metastatic disease, stress fractures, osteomyelitis, Paget's disease, avascular necrosis. Remains the workhorse bone imaging study despite growing NaF PET/CT use in high-volume centers.
Clinical pathway
- IV injection of 20–30 mCi Tc-99m MDP.
- Three-hour uptake period — patient encouraged to hydrate and void before imaging.
- Whole-body planar imaging — anterior + posterior, 10–15 min scan time.
- SPECT or SPECT/CT of area of interest — spine, pelvis, skull as indicated.
- Reporting — photopenic and hypermetabolic foci, superscan pattern in diffuse metastatic disease.
Typical systems
SPECT/CT resolves scintigraphic foci against anatomy — standard of care for indeterminate planar findings.
Room + procedure characteristics
- Total visit: 4 hours (injection + uptake + scan)
- Dose: ~6 mSv effective dose per study
- Team: nuclear medicine tech + nuclear radiologist