Article Figures & Data
Figures
- FIGURE 1.
SPECT acquisition protocols in this study. (A) Phantom study. Images are acquired for 3.5 min with 6 rotations and subsequently 7.5 min with 16 rotations. (B) Brain perfusion SPECT protocol using 99mTc-ethyl cysteinate dimer in clinical study. Images are acquired for 21 min [(3.5 min/rotation) × 6 rotations], beginning 15 min after injection.
- FIGURE 2.
(A) ROI for phantom study set to surround whole brain on anterior planar image of projection data. (B) ROI for clinical study set to surround normal or mild side on anterior planar image of projection data.
- FIGURE 3.
Representative slices of images for visual analysis. Images were created from 10 types of projection data with different acquisition counts (123.6, 92.3, 61.0, 30.8, 23.6, 19.9, 16.0, 12.0, 7.9, and 4.0 counts per pixel).
- FIGURE 4.
NMSE as function of counts per pixel in brain phantom.
- FIGURE 5.
Differential value of NMSE as function of counts per pixel.
- FIGURE 6.
Relationship between average visualization score and each range of counts per pixel. *Versus 40 counts per pixel or more, P < 0.01.
- FIGURE 7.
Typical brain perfusion images using statistical image analysis obtained at different counts in patient: reference images obtained at 32.9 counts per pixel (A) and images obtained at 6.2 counts per pixel (B). False-positives were observed in specific VOI (red border).
Tables
- TABLE 1.
Average and SD of CNR at Different Counts per Pixel in patients with degenerative nerve diseases (n = 22) and cerebrovascular diseases (n = 3)
Parameter 6 rotations 5 rotations 4 rotations 3 rotations 2 rotations 1 rotation Counts per pixel 33.6 (±4.25) 28.3 (±3.55) 22.7 (±2.86) 17.2 (±2.17) 11.5 (±1.45) 5.9 (±0.73) Normalized CNR 1.00 (±0.0) 0.99 (±0.08) 0.96 (±0.10) 0.92 (±0.16) 0.84 (±0.17)* 0.56 (±0.25)* ↵* Versus 33.6 counts per pixel, P < 0.01.
- TABLE 2.
Average and SD of Indices (Severity, Extent, and Ratio) at Different Counts per Pixel in Patients with Degenerative Nerve Diseases (n = 22)
Parameter 6 rotations 5 rotations 4 rotations 3 rotations 2 rotations 1 rotation Counts per pixel 33.9 (±4.45) 28.5 (±3.72) 22.9 (±2.99) 17.3 (±2.28) 11.6 (±1.52) 5.9 (±0.77) Normalized severity 1.00 (±0.0) 1.01 (±0.05) 1.05 (±0.06) 1.05 (±0.08) 1.07 (±0.15) 1.50 (±0.47)* Normalized extent 1.00 (±0.0) 1.00 (±0.12) 1.11 (±0.15) 1.18 (±0.55) 1.11 (±0.41) 2.34 (±2.12)* Normalized ratio 1.00 (±0.0) 0.97 (±0.11) 1.02 (±0.14) 1.01 (±0.51) 0.84 (±0.28) 1.33 (±1.17) ↵* Versus 33.9 counts per pixel, P < 0.01.
