Table 4.

Morphological computed tomography (CT), CT texture analysis (CTTA), and 18-fluorodeoxyglucose positron emission tomography/CT (FDG PET/CT) parameters for malignant and benign lymph nodes

	Benign	Malignant	P value
Morphological CT parameters, including lymph nodes, n	71	61
Location of primary tumor and lymph node
Ipsilateral	25 (50.7)	40 (65.6)	0.384
Contralateral	19 (26.8)	12 (19.7)
Subcarinal	3 (4.2)	2 (3.3)
Short axis diameter, mm	11.2 ± 4.2	15.7 ± 6.3	< 0.0001
Long axis diameter, mm	16.2 ± 5.2	22.2 ± 7.6	< 0.0001
Shape, round	7 (9.9)	10 (16.4)	0.264
Margin, well-defined	64 (90.1)	52 (85.3)	0.390
Noticeability (>  60 HU)	52 (73.2)	38 (62.3)	0.178
CT texture parameters, including lymph nodes	66	51
Area (mm2)	160.3 ± 111.1	338.8 ± 263.5	< 0.0001
Circularity	0.84 ± 0.07	0.83 ± 0.07	0.358
Compactness	0.97 ± 0.01	0.98 ± 0.01	0.003
Roundness	0.76 ± 0.08	0.77 ± 0.07	0.544
Entropy	6.6 ± 0.5	6.8 ± 0.5	0.142
Mean HU	69.6 ± 23.5	68.3 ± 23.0	0.774
Standard deviation (SD)	43.2 ± 19.6	38.0 ± 13.6	0.108
Normalized SD*	0.19 ± 0.13	0.10 ± 0.08	< 0.0001
Skewness	−0.00 ± 0.02	0.00 ± 0.02	0.562
Kurtosis	3.1 ± 0.7	3.2 ± 0.9	0.914
10th percentile HU	11.8 ± 31.9	19.3 ± 26.3	0.174
25th percentile HU	41.2 ± 24.7	42.2 ± 23.2	0.816
50th percentile HU	71.7 ± 23.0	68.1 ± 23.2	0.397
75th percentile HU	101.0 ± 28.0	94.4 ± 26.4	0.194
90th percentile HU	125.0 ± 36.3	116.4 ± 32.1	0.185
FDG PET/CT parameter, Included lymph nodes	51	52
SUVmax	3.4 ± 2.4	6.3 ± 3.8	< 0.0001
SUVPeak	2.7 ± 1.6	5.2 ± 3.1	< 0.0001
Maximal HU†	119.1 ± 283.5	80.4 ± 147.3	0.385
SUVmax ≥ 2.5 and HU < 70	15 (29.4)	40 (76.9)	< 0.0001

Data presented as n (%) or mean ± standard deviation, unless otherwise indicated

*Normalized standard deviation (SD) is calculated as In(SD)/In(n)[=In(SD)/In(total number of pixels within the region of interest)]

HU, Hounsfield unit; SUV, standard uptake value

^† HU values obtained from non-enhanced chest CT performed with FDG PET/CT