99mTc-Pyrophosphate Cardiac Amyloidosis Imaging Parameters
| Parameter | Characteristics | Standard/optional/preferred |
|---|---|---|
| Camera type | Large-field-of-view γ-camera | Standard |
| Cadmium zinc telluride | Optional* | |
| Energy peak | 140 keV | Standard |
| Energy window | 15%–20% | Standard |
| Collimator | Low-energy, all-purpose | Standard |
| Patient position | Supine | Standard |
| Field of view | Heart/chest | Standard |
| Injection-to-imaging time | 3 h | Standard |
| 1 h | Optional | |
| Planar | ||
| Acquisition type | Static | Standard |
| Whole-body imaging | Optional† | |
| Detector configuration | 90° | Standard |
| Views | Anterior and left lateral | Standard |
| Number of views | 2 | Standard |
| Counts per view | 750,000 | Standard |
| Matrix | 256 × 256 | Standard |
| Magnification | 1.46 | |
| SPECT or SPECT/CT* | ||
| Acquisition type | Step and shoot or continuous | Standard |
| Patient position | Supine | Standard |
| Upright | Optional | |
| Orbit | 180°/90° | Standard |
| 360°/180° | Optional | |
| Matrix | 128 × 128 (minimum, 64 × 64) | Standard |
| Magnification | 1.46 (180° orbit) | Standard |
| 1.0 (360° orbit) | Optional | |
| Pixel size | 2.3–6.5 mm | Standard |
| Projections per detector | 40/32 | Standard |
| Time per projection | 20 s/25 s | Standard |
| CT attenuation correction | Heart | Preferred |
↵* Parameters defined for γ-cameras as parameters for cadmium-zinc-telluride cameras have not been firmly established.
↵† Whole-body imaging is not useful when imaging with 99mTc-pyrophosphate. However, when using 99mTc-hydroxymethylenediphosphonate or 99mTc-DPD, whole-body imaging is useful to demonstrate soft-tissue uptake.