Table 3.

Microbubble contrast agent imaging strategies

	Transmitted pulse	Radiofrequency (fast-time) filter	Pulse-to- pulse (slow- time) filter	Reference
Single pulse strategies
Harmonic (Narrowband)	Multicyle pulse with a center frequency near the microbubble resonance and low amplitude	High pass	N/A	(Villanueva, 1995)
Transient (Wideband)	Single cycle pulse with a center frequency of ~ 2MHz and PRP of ~200- 500kPa	High pass	N/A	(Kruse and Ferrara, 2005)
Subharmonic	Multicyle pulse with a center frequency either near the microbubble resonance or a multiple of resonance	Low pass	N/A	(Cheung et al., 2008; Chomas et al., 2002; Forsberg et al., 2000; Shankar et al., 1998; Shi et al., 1999)
Coded excitation	Many possible codes	Many possible filtering methods	Can be extended to multi-pulse strategy	(Borsboom et al., 2004; Borsboom et al., 2005; Gong et al., 2007; Sun et al., 2007)
Low power multipulse strategies
Harmonic Power Doppler	Sequential pulses as in the harmonics above	High pass	High pass (difference between returns)	(Senior et al., 2000; Simpson et al., 2001; Bauer et al., 1999; Chang et al., 1995)
Phase Inversion	Sequential harmonic or transient pulses with phase shift between transmission	Often high pass but not required	Low pass (sum of returned echoes)	(Graubner et al., 1997; Burns et al., 2000; Harvey et al., 2000a; Harvey et al., 2000b; Morgan et al., 1998)
Dual frequency- radial modulation	Sequential or simultaneous transmission of harmonic pulses with varied center frequency	Low pass		(Chen et al., 2006b; Masoy et al., 2008; Cherin et al., 2008)
Power modulation	Sequential pulses differing in pressure amplitude	Not required	Scale and subtract	(Porter et al., 2003; Brock-Fisher and Prater, 2006)
CPS	Sequential pulses differing in pressure and phase	Not required	Low pass (sum of returned echoes)	(Phillips and Gardner, 2004; Solbiati et al., 2004; Stieger et al., 2008).
High power multipulse strategies
Destruction- reperfusion	Train of similar pulses is transmitted	Varied	Loss of correlation or changes in echo amplitude are assessed	(Wei et al., 1998; Wei et al., 2001a; Wei et al., 2001b; Chomas et al., 2003; Krix et al., 2004; Potdevin et al., 2004; Dijkmans et al., 2004)