Table 1.

Ultrasound contrast enhancers having been used in brain perfusion studies (adapted from [16]).

Name	First Approved	Gas	Shell Material	Producer/Distributor
Levovist®	1993, withdrawn	Air	Galactose microparticles	Schering AG, Berlin, DE
Optison®	1998	Octafluoropropane, C3F8	Cross-linked serum albumin	GE healthcare, Buckinghamshire, UK
SonoVue®	2001	Sulphurhexafluoride, SF6	Phospholipid	Bracco diagnostics, Milano, Italy