Table 2 Univariate and multivariate analyses of preoperative clinical and MRI risk factors for LNM in NF -PNETS in the training cohort

Gender (male/female)

18/27

11/10

0.350

Age, year

52.87 ± 12.19

55.62 ± 12.03

0.390

BMI, kg/m²

24.75 ± 3.89

24.06 ± 4.40

0.520

Symptom (present or absent)

23/22

11/10

0.920

NLR (mean ± SD)

2.29 ± 1.39

3.02 ± 4.02

0.510

TB (< 21/ ≥ 21), μmol/L

40/5

13/6

0.070

ALT (< 40/ ≥ 40), IU/L

42/3

13/6

0.016

AST (< 40/ ≥ 40), IU/L

43/2

14/7

0.003

FBG (< 6.1/ ≥ 6.1), mmol/L

30/14

10/9

0.240

CEA (< 5/ ≥ 5), ng/ml

36/5

18/1

0.650

CA199 (< 37/ ≥ 37), U/ml

39/2

13/6

0.010

CA724 (< 5.9/ ≥ 5.9), U/ml

28/1

17/0

 > 0.999

NSE (< 16.3/ ≥ 16.3), ng/ml

22/9

9/6

0.510

Tumor location (head or neck/ body/tail)

24/12/9

10/6/5

0.900

SI on T2WI (hypointense/ isointense/hyperintense)

2/31/12

3/14/4

0.360

Maximum diameter of the tumor (< = 20/ > 20 mm)

15/30

3/18

0.106

Tumor margin (regular/ irregular)

29/16

6/15

0.007

4.722(1.093–20.404)

0.038*

Exophytic growth (present or absent)

23/22

13/8

0.410

MPDD or CBDD (present or absent)

11/34

12/9

0.009

Hyperenhancement at arterial phase (present or absent)

27/18

7/14

0.043

Homogeneity (present or absent)

33/12

9/12

0.017

Vascular and adjacent tissue involvement (present or absent)

6/39

9/12

0.012

Synchronous liver metastases

7/38

11/10

0.002

Long axis of the largest lymph node, mm

7.44 ± 6.25

15.52 ± 6.64

 < 0.001*

Short axis of the largest lymph node, mm

4.11 ± 3.26

10.05 ± 4.93

 < 0.001*

1.488(1.162–1.907)

0.002*

Ratio of the long axis to the short axis of the largest lymph node

1.87 ± 0.62

1.61 ± 0.31

0.150

Irregular shape of the largest lymph node (present or absent)

3/42

10/11

 < 0.001*

Number of the lymph nodes with the short axis > 5 mm

0.71 ± 0.87

2.24 ± 1.70

 < 0.001*

Number of the lymph nodes with the short axis > 10 mm

0.09 ± 0.42

0.95 ± 1.16

 < 0.001*

ADC_mean (× 10^–3 mm²/s)

1453.85 ± 314.02

1505.07 ± 755.50

0.600

ADC_max (× 10^–3 mm²/s)

2371.39 ± 590.96

2917.76 ± 1754.11

0.350

ADC_min (× 10^–3 mm²/s)

574.80 ± 691.29

337.94 ± 524.81

0.007

Tumor volume, mm³

32,301.35 ± 67,882.65

139,198.20 ± 447,799.03

0.140