Table 2. The results of subgroup analysis for DWI and PET/CT.

Factors	No.of studies	Sensitivity (95%CI)	Specificity (95%)
DWI
Sample size
< 250	6	0.73 (0.66–0.79)	0.90 (0.87–0.93)
≥ 250	4	0.71 (0.66–0.77)	0.98 (0.98–0.99)
Study design*
Prospective	6	0.72 (0.67–0.77)	0.98 (0.97–0.98)
Retrospective	4	0.72 (0.63–0.79)	0.81 (0.74–0.88)
Consecutive enrollment*
Yes	6	0.72 (0.67–0.77)	0.98 (0.97–0.98)
No/Unclear	4	0.72 (0.63–0.79)	0.81 (0.74–0.88)
PET/CT
Sample size
< 250	9	0.68 (0.63–0.72)	0.86 (0.84–0.88)
≥ 250	29	0.64 (0.63–0.66)	0.94 (0.93–0.94)
Study design
Prospective	15	0.67 (0.64–0.69)	0.94 (0.94–0.95)
Retrospective	23	0.63 (0.61–0.66)	0.92 (0.91–0.93)
Country
non-Asia	10	0.66 (0.63–0.70)	0.93 (0.92–0.94)
Asia	28	0.64 (0.62–0.67)	0.93 (0.93–0.94)
Consecutive enrollment
Yes	26	0.64 (0.61–0.66)	0.95 (0.94–0.95)
No/Unclear	12	0.68 (0.65–0.71)	0.90 (0.89–0.91)
Blind
Yes	24	0.65 (0.62–0.67)	0.93 (0.93–0.94)
No/Unclear	14	0.65 (0.62–0.68)	0.93 (0.92–0.93)
Analysis method
QN	19	0.67 (0.65–0.69)	0.93 (0.93–0.94)
QL	16	0.62 (0.60–0.65)	0.93 (0.92–0.94)
QN+QL	3	0.61 (0.52–0.70)	0.93 (0.90–0.95)

ND: no document; No.: number; QN: quantitative; QL: qualitative.

*There is significant difference between these subgroups.