Image Acquisition Parameters (3,5)
| Dynamic flow | Static | SPECT |
|---|---|---|
| Anterior | Anterior for blood pool images; additional static images include posterior and laterals | Only if using 99mTc-HMPAO or 99mTc-ECD and only as needed |
| 1–3 s/frame for 1–2 min | 500,000–1,000,000 counts per image | Time per stop and counts acquired dependent on radiopharmaceutical dose administered (e.g., 64 projections, 20–40 s/stop [200,000 counts]); use of institutional guideline for other brain SPECT studies |
| 15%–20% window around 140-keV photopeak | 15%–20% window around 140-keV photopeak | 15%–20% window around 140-keV photopeak |
| 128 × 128 matrix | 128 × 128 matrix | At least 128 × 128 matrix |
| LEAP, LEHR collimators | LEAP, LEHR collimators | LEAP, LEHR, or UHR collimators; fanbeam or other focused collimator is needed for increased resolution and higher counting rates |
| Zooming or magnification optional | Zooming or magnification optional | Zoom set to produce pixel size of 3.5 mm or less |
| Circular or noncircular orbit with smallest radius possible | ||
| Continuous or step-and-shoot |
LEAP = low-energy all-purpose; LEHR = low-energy high-resolution; UHR = ultrahigh resolution.