Table 3.

Results of multiple univariable meta-regression to determine possible sources of heterogeneity of the sensitivity and specificity estimates

Covariates		No. of primary studies	Pooled sensitivity (95% CI)	p value	Pooled specificity (95% CI)	p value
Study design	Retrospective	12	75% (65 to 85%)	0.37	75% (66 to 83%)	0.23
	Prospective	2	91% (80 to 100%)		65% (42 to 89%)
Mean size of malignant lesions	<36 mm	5	67% (51 to 84%)	0.02	77% (67 to 88%)	0.83
	≥36 mm	6	83% (73 to 93%)		65% (52 to 77%)
Mean size of benign lesions	<25.71 mm	5	80% (68 to 93%)	0.92	68% (55 to 81%)	0.08
	>25.71 mm	5	67% (51 to 84%)		75% (64 to 87%)
Only HCC in malignant group	Yes	5	74% (57 to 90%)	0.12	74% (61 to 87%)	0.17
	No	9	80% (70 to 91%)		74% (64 to 84%)
Dysplastic nodules as benign lesions	Yes	3	70% (47 to 93%)	0.19	84% (69 to 99%)	0.87
	No	11	80% (70 to 89%)		71% (62 to 80%)
Sample size	<65 lesions	7	73% (58 to 88%)	0.7	72% (59 to 84%)	0.26
	≥65 lesions	7	81% (70 to 92%)		74% (63 to 85%)
MRI vendor	Siemens	10	75% (63 to 87%)	0.08	73% (63 to 84%)	0.22
	GE	4	85% (72 to 98%)		77% (61 to 93%)
Diffusion-weighted sequence	SS-SE-EPI	5	75% (60 to 91%)	0.18	81% (71 to 91%)	0.79
	SS-EPI	8	80% (69 to 92%)		68% (56 to 79%)
Breathing pattern of DW-MRI	Breath-hold	5	63% (46 to 81%)	<0.001	77% (65 to 90%)	0.37
	Non-breath-hold	9	84% (76 to 92%)		72% (61 to 83%)
Maximal b value for DWI	≥800	9	80% (69 to 90%)	0.57	75% (65 to 84%)	0.26
	<800	5	75% (58 to 92%)		72% (58 to 86%)
Slice thickness	≤6 mm	9	80% (69 to 91%)	0.19	72% (61 to 83%)	0.33
	7 or 8 mm	5	75% (57 to 92%)		76% (64 to 89%)
Patient selection	High/unclear risk of bias	4	74% (55 to 99%)	0.21	79% (66 to 92%)	0.58
	Low risk of bias	10	79% (69 to 90%)		71% (61% to 81%)

DWI, diffusion-weighted imaging; HCC, hepatocellular carcinoma; SS-EPI, single-shot echoplanar imaging.