Reasons for False-Positive and False-Negative Studies
| Study category | Reason |
|---|---|
| False-positive | Residual cardiac blood pool |
| Rib activity (e.g., prior fracture or metastasis) | |
| Mitral valve and annular calcification | |
| Pericarditis | |
| Chemotherapy | |
| Myocardial toxic drugs (e.g., hydroxychloroquine) | |
| Recent myocardial infarction (<6 wk) | |
| False-negative | Minimal myocardial uptake in early disease stages |
| Amyloidosis variants that do not accumulate 99mTc-pyrophosphate (e.g., Phe64Leu or Val30Met) | |
| Large old myocardial infarction |