Reference phantom properties: | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Simulated structure | Density (HU) | Dimensions [AP, LR, SI] (mm) | Shape | ||||||||||||
Body | 0.0 | 220 × 150 × 120 | |||||||||||||
Parotid gland left (Pl) | -100 | 60 × 24 × 50 | Ellipsoidal | ||||||||||||
Parotid gland right (Pr) | -200 | 40 × 12 × 30 | Ellipsoidal | ||||||||||||
Tumor (T) | 250 | 60 × 40 × 20 | Ellipsoidal | ||||||||||||
Vertebrae (V) | 1000 | 28 × 24 | Tubical | ||||||||||||
Spinal cord (S) | 200 | 12 × 12 | Tubical | ||||||||||||
Two bony structures near parotid glands | 1000 | 16 × 12 × 12 | Square | ||||||||||||
Discs (spacing of 1.0 mm) | -250 - 250 | 12 × 4.0 | Tubical | ||||||||||||
Phantom images: | Ref. | I | II | III | IV | V | VI | VII | VIII | IX | X | XI | XII | XII I | XIV |
Image noise (1SD, ± HU) | 20 | 40 | 80 | 100 | 200 | 20 | 40 | 80 | 100 | 200 | 20 | 40 | 80 | 100 | 200 |
Grey value factor discs (GF) | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 |
Contrast-to-noise ratio (CNR) | 17.5 | 8.75 | 4.38 | 3.50 | 1.75 | 11.3 | 5.63 | 2.81 | 2.25 | 1.13 | 23.8 | 11.9 | 5.94 | 4.75 | 2.38 |
Phantom images: | XV | XVI | XVII | ||||||||||||
Diameter discs (mm) | 6.0 | 6.0 | 6.0 | ||||||||||||
Spacing discs (mm) | 1.0 | 7.0 | 19 |