Table 1.

Basic information of included studies

Nation	Authors	Year	Cases	Mean age	Imaging
					modality
United States	B. Ackman et al.	2014	160	51(15-87)	CT
	T. Araki et al.	2014	18	56(37-79)	CT
Korea	Chang et al.	2017	37	54	CT
Italy	Priola et al.	2016	83	38.4(14-71)	CT/MRI
Japan	Seki et al.	2014	35	51.6(22-75)	CT/MRI
Japan	Tomiyama et al.	2009	127	45.9(10-82)	CT/MRI
Japan	Usuda et al.	2015	16	*	MRI
Japan	H. Yabuuchi et al.	2015	48	50.7(21-83)	MRI

*: unmentioned