Page 96 - Quantitative Imaging of Small Tumours with Positron Emission Tomography
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 A 80 60 40 20 100% counts 50% counts B 80 60 +29.3% 40 +30.6% +28.2% 20 +29.8% 00 -22.3% -20 -24.1% -28.2% -40 -29.8% -60 -800 5 10 15 20 25 average SUVmean (test-retest) D 80 60 40 +30.2% 40 +32.1% 4 -20 -40 -60 -800 5 10 15 20 25 average SUVmean (test-retest) C 80 60 +30.2% 20 +31.4% 00 20 -20 -23.0% -20 -24.7% -40 -32.1% -60 -800510152025 average SUVpeak (test-retest) [18F]FDHT PET repeatability %difference %difference %difference %difference %difference %difference -40 -30.2% -60 -800 5 10 15 20 25 average SUVpeak (test-retest) E 80 60 40 20 +35.9% +39.0% F 80 60 40 20 00 -20 -20 -27.4% -40 -35.9% -60 -800 10 20 30 40 average SUVmax (test-retest) -30.1% +34.2% +36.2% Figure 4.7: Bland-Altman graph of interscan (test-retest) variability of SUVmean (A and B), SUVpeak (C and D), and SUVmax (E and F) normalized to bodyweight at 100% and 50% of counts. Results from both EARL1 images (A, C, E) and EARL2 images (B, D, F) are shown. Lesion detectability In general, the impact of count reduction on lesion detectability was small, with a median 4.6% (IQR 1.2-8.7%) reduction in CNR from median 3.7 (IQR 3.1-4.3) to 3.5 (IQR 2.9-4.1) on EARL1 images after count reduction. For EARL2 images, there was a median 4.6% (IQR 1.2-8.7%) reduction in CNR from median 3.9 (IQR 3.1-4.7) to 3.7 (IQR 2.9-4.5) after count reduction. -40 -39.0% -60 -80010203040 average SUVmax (test-retest) 95 


































































































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