Table 2 Standard mean difference of subgroup analyses on apparent diffusion coefficient values of diffusion-weighted magnetic resonance imaging in differential diagnosis of renal tumors

Ethnicity:

Asians

2.54

1.71-3.37

<0.001

0.22

−1.45-0.77

0.016

2.84

1.30-4.39

< 0.001

Caucasians

1.85

1.24-2.45

< 0.001

−1.07

0.43-2.62

0.013

-

-

-

Africans

-

-

-

−1.00

−1.74-(−0.26)

0.008

-

-

-

Machine type:

GE

1.73

0.94-2.52

< 0.001

−0.05

−0.21-0.30

0.713

0.74

−0.55-2.04

0.259

SIEMENS

3.34

1.50-5.17

< 0.001

−0.58

−0.91-(−0.26)

< 0.001

4.21

3.14-5.28

< 0.001

PHILIPS

2.52

1.07-3.98

0.001

2.21

1.90-2.53

< 0.001

4.15

1.56-6.73

0.002

b value:

500

2.08

1.11-3.05

< 0.001

1.85

1.48-2.22

< 0.001

3.36

1.22-5.49

0.002

600

0.94

0.47-1.41

< 0.001

−0.27

−0.70-0.17

0.233

−0.10

−0.53-0.34

0.664

800

2.22

0.97-3.48

0.001

1.43

0.95-1.90

< 0.001

2.99

−1.82-7.80

0.223

1000

2.55

−0.37-5.48

0.087

0.59

0.25-0.93

0.001

3.11

−2.87-9.08

0.308

400/800

-

-

-

−1.37

−1.93-(−0.82)

< 0.001

-

-

-

500/1000

4.19

3.45-4.93

< 0.001

−0.18

−0.58-0.22

0.375

4.21

3.14-5.28

< 0.001