Table 1. Main characteristics of the eligible studies.

First author	Year	country	Ethnicity	types of liver diseases	Total number	Diseased liver	Diseased liver with liver metastases	Non-diseased liver	Non-diseased liver with livermetastases
Uetsuji	1992	Japan	Asian	Cirrhosis	250	46	0	204	40
Hayashi	1997	Japan	Asian	Fatty liver	839	121	2	718	115
Utsunomiya	1999	Japan	Asian	Hepatitis infection	438	37	3	401	85
Song	2001	China	Asian	Hepatitis infection	512	74	10	438	119
Iasome	2005	Italy	Caucasian	Hepatitis infection/cirrhosis/fatty liver	834	291	28	543	174
Qian	2010	China	Asian	Hepatitis infection/cirrhosis	2352	140	11	2212	517
Qiu	2011	China	Asian	Hepatitis infection	1298	332	47	966	272
Wang	2012	China	Asian	Hepatitis infection	354	70	2	284	48
Zeng	2013	China	Asian	Hepatitis infection	2868	373	33	2495	465
Murono	2013	Japan	Asian	Fatty liver	604	63	2	541	52