Skip to main content

Table 3 Contrast-noise ratio (CNR) for volumetric imaging and steak artefact index (SI) on X-ray volumetric imaging for different fiducial markers

From: Fiducial markers visibility and artefacts in prostate cancer radiotherapy multi-modality imaging

Volumetric imaging

Visibility (CNR)

 

Artefact (SI)

RP

CIVCO

GA

GA (B)

PM

 

RP

CIVCO

GA

GA(B)

PM

CT (slice thickness (mm))

 0.625

1.46

1.49

1.53

1.54

1.47

 

67.78

110.9

61.04

67.51

25.57

 1.25

1.61

1.46

1.44

1.22

1.52

 

86.92

52.81

65.20

59.64

66.24

 2.5

1.27

1.23

1.42

1.34

1.52

 

53.35

47.19

36.88

46.15

11.63

CBCT (protocol)

 P Varian

1.17

0.96

0.99

0.92

0.79

 

33.16

22.03

33.81

13.86

19.55

 P Medium

0.94

0.94

0.64

1.07

0.90

 

26.38

42.57

15.58

19.91

9.82

 P Obese

1.00

0.84

0.85

1.16

1.27

 

66.08

58.28

47.48

75.81

36.88

MRI

FM size (mm3)

 

P

13.57

13.57

5.03

5.03

9.42

 T1w

1.17

1.69

1.77

1.64

2.56

 

6.67

10.00

6.67

26.67

3.33

 T2w (filtered)

1.95

1.87

1.54

1.45

1.88

 

13.33

20.00

16.67

23.33

13.33

 VIBE

1.58

1.94

1.57

1.47

2.10

 

53.33

70.0

123.33

136.67

110.00

  1. Note that CNR and SI values are calculated for each box as a contribution of the 3 FMs contained in each box while FM size in MRI corresponds to one FM to facilitate the comparison with their physical dimensions. P indicates the physical size of the markers calculated assuming the markers are perfect cylinders
Back to article page

Radiation Oncology

ISSN: 1748-717X

Contact us