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Table 1 Phantom characteristics

From: The effects of computed tomography image characteristics and knot spacing on the spatial accuracy of B-spline deformable image registration in the head and neck geometry

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

            
  1. Ref. indicates the characteristics of the reference phantom (see Figure 1).