Article Figures & Data
Figures
- FIGURE 1.
Method of extracting PET acquisition data of various scan times from long list-mode data. Fifteen PET images for each scan time were generated, totaling 76 PET images.
- FIGURE 2.
All PET images obtained in this study are shown. Images are not identical even with the same scanning time. Visualization of hot spheres depend on scanning time.
- FIGURE 3.
(A) PET images having highest (#12) and lowest (#2) SUVmax,10 among the 15 frames of the 60-s scan. SUVmax,10 fluctuates considerably. (B) Three-dimensional graphics of 37-mm-diameter hot sphere with 1,800- and 60-s scan times. Maximum pixel value of small hot sphere in low-count-statistics image was often higher than that in high-count-statistics image.
- FIGURE 4.
SUVmax and SUVpeak in relation to sphere sizes and scan times. SUVmax,37 for 60-s image had positive biases of 28.3%, compared with SUVref,max,37. SUVmax was overestimated as sphere size increased and scanning time decreased. SUVpeak was almost constant irrespective of scan time.
Tables
- TABLE 1
Variability (CV) of SUVmax and SUVpeak of Hot Spheres and Background in Relation to Scanning Time
Scan time (s) Index 60 90 120 150 180 CVmax,10 11.0 10.9 11.6 8.8 8.5 CVmax,13 7.0 6.7 6.0 6.2 5.3 CVmax,17 8.8 7.9 7.0 5.6 4.8 CVmax,22 6.3 7.1 6.2 5.9 4.5 CVmax,28 5.7 4.5 3.9 3.0 2.7 CVmax,37 3.1 2.0 2.7 1.8 2.1 CVpeak,13 3.5 3.6 3.5 3.4 2.7 CVpeak,17 3.3 3.8 3.4 2.8 2.1 CVpeak,22 4.6 3.0 2.7 2.7 2.9 CVpeak,28 3.1 3.1 2.8 2.1 2.2 CVpeak,37 2.3 2.4 2.1 2.2 1.5 CVbackground 16.5 13.6 11.8 10.7 9.8 N10 mm 10.1 8.5 7.6 6.9 6.1 Scan time (sec) Index 60 90 120 150 180 %Diffmax,10 12.9 8.5 8.4 7.0 7.2 %Diffmax,13 9.4 9.1 6.9 6.4 6.0 %Diffmax,17 11.0 9.1 7.5 7.0 5.7 %Diffmax,22 14.4 12.8 8.9 8.4 6.6 %Diffmax,28 22.7 15.9 13.7 11.4 10.2 %Diffmax,37 28.3 19.1 16.6 13.7 12.3 %Diffpeak,13 3.7 3.5 3.1 2.8 2.3 %Diffpeak,17 2.8 2.7 2.7 2.4 1.8 %Diffpeak,22 3.4 2.3 2.3 2.3 2.4 %Diffpeak,28 3.2 2.7 2.2 1.7 1.8 %Diffpeak,37 4.4 4.3 3.0 2.9 2.3
