Frequent Causes of Different Tracer Uptake Patterns in Brain Perfusion SPECT Images
| Tracer uptake pattern | Cause |
|---|---|
| Cold (no uptake) | Cerebrospinal fluid |
| Edema | |
| Necrosis | |
| Space-occupying lesions (e.g., hemorrhage, tumors,* cysts, arteriovenous malformation, postsurgery) | |
| Hypoactive (decreased uptake) | Ischemia |
| Hypometabolism (hypofunction): degeneration, deafferentation | |
| Atrophy | |
| Hyperactive (increased uptake) | Luxury perfusion |
| Encephalitis | |
| Acetazolamide-induced vasodilation | |
| Hyperfunction (epilepsy [ictal], neuroactivation, other causes of increased neuronal activity) | |
| Tumors* |
↵* Tumors can produce a variety of patterns in SPECT perfusion images. The most frequent tumors with increased tracer uptake are meningiomas.