Table 3:

Clustering Reproducibility of All Radiomic Features, Reproducible Radiomic Features, and Reproducible Corrected Radiomic Features according to Changes in Technical Parameters

Parameter	All Radiomic Features	Reproducible Radiomic Features	Reproducible and Corrected Radiomic Features	P Value for Random Features vs Reproducible Features	P Value for Corrected Random Features vs Reproducible Corrected Features
Section thickness (reference value, 3.0 mm)
1.0 mm	0.14 (0.07, 0.2)	0.43 (0.3, 0.56)	0.59 (0.45, 0.69)	<.001	<.001
5.0 mm	0.14 (0.07, 0.22)	0.36 (0.26, 0.5)	0.71 (0.57, 0.83)	.001	<.001
Dose level (reference value, 100%)
Dose level 25%	0.18 (0.11, 0.29)	0.32 (0.21, 0.47)	0.55 (0.41, 0.72)	.02	<.001
Dose level 37%	0.19 (0.11, 0.28)	0.36 (0.26, 0.47)	0.47 (0.32, 0.62)	.006	.001
Dose level 50%	0.2 (0.11, 0.3)	0.4 (0.26, 0.59)	0.51 (0.38, 0.64)	.01	<.001
Dose level 62%	0.27 (0.19, 0.39)	0.35 (0.2, 0.49)	0.48 (0.34, 0.66)	.14	.02
Dose level 75%	0.37 (0.25, 0.49)	0.33 (0.2, 0.49)	0.39 (0.25, 0.55)	.59	.06
Dose level 87%	0.47 (0.34, 0.6)	0.46 (0.32, 0.59)	0.51 (0.38, 0.66)	.45	.007
Algorithm (reference, FBP)
SAFIRE strength 1	0.28 (0.22, 0.38)	0.28 (0.18, 0.36)	0.51 (0.42, 0.6)	.46	.154
SAFIRE strength 2	0.18 (0.1, 0.27)	0.26 (0.14, 0.4)	0.57 (0.43, 0.73)	.13	.009
SAFIRE strength 3	0.15 (0.09, 0.23)	0.31 (0.2, 0.41)	0.5 (0.39, 0.66)	.02	.02
SAFIRE strength 4	0.14 (0.07, 0.21)	0.29 (0.18, 0.41)	0.42 (0.32, 0.53)	.02	.01
SAFIRE strength 5	0.13 (0.07, 0.2)	0.32 (0.21, 0.44)	0.46 (0.34, 0.62)	.003	<.001
Kernel (reference, B30)
B20f	0.15 (0.09, 0.22)	0.32 (0.24, 0.44)	0.44 (0.34, 0.55)	.01	.023
B35f	0.19 (0.12, 0.24)	0.4 (0.26, 0.53)	0.59 (0.47, 0.7)	.004	.001
B40f	0.27 (0.16, 0.36)	0.55 (0.4, 0.72)	0.67 (0.53, 0.78)	.006	.001
B41f	0.32 (0.23, 0.43)	0.58 (0.47, 0.7)	0.58 (0.47, 0.74)	.004	.003
D30f	0.3 (0.2, 0.41)	0.54 (0.42, 0.68)	0.55 (0.45, 0.69)	.001	.004
Br36f	0.17 (0.1, 0.25)	0.36 (0.26, 0.47)	0.59 (0.48, 0.7)	.008	<.001
Br40f	0.26 (0.16, 0.38)	0.54 (0.37, 0.72)	0.68 (0.54, 0.81)	.01	<.001
Bf39f	0.33 (0.23, 0.43)	0.58 (0.47, 0.7)	0.57 (0.47, 0.74)	.002	.005
Bf42f	0.19 (0.11, 0.28)	0.44 (0.3, 0.6)	0.60 (0.48, 0.75)	.006	<.001
Qr36f	0.17 (0.09, 0.26)	0.36 (0.24, 0.47)	0.59 (0.47, 0.69)	.006	<.001
Qr40f	0.31 (0.22, 0.42)	0.64 (0.49, 0.8)	0.67 (0.5, 0.82)	<.001	<.001

Note.—Data are nonparametric correlation values (ρ values [range, 0–1, with 1 representing perfect agreement]) between two hierarchical clusters based on radiomic features for which half of patients were scanned by using the reference CT technique and half were scanned by using an alternative technique. FBP = filtered back projection, SAFIRE = sinogram-affirmed iterative reconstruction. Data in parentheses are 95% confidence intervals; P < .05 was considered to indicate a significant difference.