Study ID	Type of ultrasound	Unit of analysis number of individuals	Unit of analysis number of scans
Abbas 2014	CE‐CDUS	‐	✔
AbuRahma 2005	CDUS	‐	✔
Arsicot 2014	CDUS	✔
Ashoke 2005b	CDUS	‐	✔
Ashoke 2005c	CDUS	‐	✔
Badri 2010	CDUS	‐	✔
Bendick 2003	CDUS/CE‐CDUS	✔	‐
Cantisani 2011	CDUS/CE‐CDUS	✔	‐
Clevert 2008b	CDUS/CE‐CDUS	✔	‐
Clevert 2011	CDUS/CE‐CDUS	✔	‐
Costa 2013	CDUS/CE‐CDUS	‐	✔
d'Audiffret 2001	CDUS	✔
Demirpolat 2011	CDUS	‐	✔
França 2013	CDUS	‐	✔
Gargiulo 2014	CE‐CDUS	✔
Giannoni 2003	CDUS/CE‐CDUS	‐	✔
Giannoni 2007	CE‐CDUS	✔	‐
Golzarian 2002	CDUS	✔	‐
Gray 2012	CDUS	‐	✔
Gurtler 2013	CE‐CDUS	‐	✔
Heilberger 1997	CDUS/CE‐CDUS	✔	‐
Henao 2006	CDUS/CE‐CDUS	✔	‐
Iezzi 2009	CDUS/CE‐CDUS	✔	‐
McLafferty 2002	CDUS	✔	‐
McWilliams 1999	CDUS/CE‐CDUS	‐	✔
McWilliams 2002	CDUS/CE‐CDUS	‐	✔
Motta 2012	CE‐CDUS	‐	✔
Nagre 2011	CDUS	‐	✔
Nerlekar 2006	CDUS	‐	✔
Oikonomou 2012	CDUS	✔	‐
Pages 2001	CDUS	‐	✔
Parent 2002	CDUS	✔	‐
Perini 2011	CE‐CDUS	✔	‐
Perini 2012	CE‐CDUS	✔	‐
Raman 2003	CDUS	‐	✔
Sandford 2006	CDUS	✔	‐
Sato 1998	CDUS	‐	✔
Schmieder 2009	CDUS	‐	✔
Ten Bosch 2010	CE‐CDUS	‐	✔
Thompson 1998	CDUS	✔	‐
Wolf 2000	CDUS	‐	✔
Zannetti 2000	CDUS	✔	‐
CDUS: colour duplex ultrasound; CE‐CDUS: contrast‐enhanced colour duplex ultrasound.