The Effect of CT Scan Parameters on the Measurement of CT Radiomic Features: A Lung Nodule Phantom Study

Table 3

Absolute effect size in 100 HU phantom nodules.

Image features			Slice thickness						mAs		Reconstruction algorithm
			5.00 vs 1.25		5.00 vs 2.50		2.50 vs 1.25		30 vs 120		Lung vs standard
			Effect	d	Effect	d	Effect	d	Effect	d	Effect	d
Histogram		Mean	<	4.62	<	2.81	<	1.18	<	0.07	>	1.02
		Stddev	>	3.06	>	1.05	>	1.40	>	0.42	>	0.59
		Variance	>	3.35	>	0.72	>	1.06	>	0.38	>	0.50
		Skewness	<	1.98	<	1.77	<	1.20	<	0.18	<	0.40
		Kurtosis	>	0.64	>	1.58	>	0.15	0	0.13	>	1.09
		Energy	<	5.63	<	2.70	<	1.44	<	0.35	>	0.74
		Entropy	>	7.06	>	3.25	>	1.67	>	0.26	<	0.65
GLCM		Contrast	<	5.73	<	2.27	<	2.26	>	0.13	>	0.15
		Dissimilarity	<	2.04	0	0.11	0	1.05	>	0.52	<	0.31
		Homogeneity	<	5.81	<	3.36	<	0.87	<	0.46	>	0.45
		ASM	<	4.20	<	2.32	<	0.79	<	0.68	>	0.57
		Energy	<	5.53	<	3.28	<	0.88	<	0.49	>	0.50
		Probability max	<	5.25	<	3.28	<	0.77	<	0.51	>	0.49
		Entropy	>	6.56	>	3.38	>	1.34	>	0.39	<	0.53
		Correlation	>	5.61	>	1.69	>	1.96	<	0.18	0	0.10
GLRLM		LRE	<	4.40	<	3.05	<	0.65	<	0.64	>	0.34
		GLN	<	5.36	<	2.96	<	1.17	<	0.40	>	0.64
		RLN	>	5.35	>	3.85	>	0.88	>	0.35	<	0.39
		LGRE	>	5.18	>	1.59	>	0.64	0	0.11	<	0.37
		HGRE	<	6.30	<	3.93	<	1.66	<	0.13	>	0.54

and A is statistically smaller than B (A vs B); and A is statistically larger than B (A vs B); 0 indicates A and B are not statistically significant (A vs B). Cohen’s d: small ≥ 0.20; medium ≥ 0.50; large ≥ 0.80.