Mean Hausdorff Distance (nasal cavity) (mm)

Mean Hausdorff Distance (pharyngeal region) (mm)

Dice Similarity Coefficient

Void Fraction (%)

Volume Ratio

Volumetric Similarity

Global Thresholding

0.28

0.2

0.85

20

0.93

1.04

Multi-step level-set

0.40

0.16

0.89

13

0.93

1.04

Thresholding

0.38

0.2

0.90

14

0.98

0.98

Clustering

0.59

0.4

0.96

6

1.53

0.79

Classification

0.36

0.16

0.92

12

1.03

1.01

Ideal value

0

0

1

0

1

0