Contrast enhanced ultrasound of hepatocellular carcinoma

Table 1 Sonazoid-enhanced US at a low mechanical index (MI)

Authors	Injection volume of Sonazoid	MI in late phase	Scan starting time in late phase
Moriyasu et al[33]	0.015 mL/kg	0.3-0.5	10 min afterinjection
Korenaga et al[42]	0.01 mL/kg	0.2-0.3	30 min after injection
Hatanaka et al[39]	0.01 mL/kg	0.2	At least 10 min after injection
Maruyama et al[44]	0.0075 mL/kg	0.24-0.3	5-10 min after injection
Numata et al[37]	0.2 mL/body	0.2	At least 5 min after injection

All examinations were conducted using contrast-enhanced phase inversion harmonic US.

Table 2 Setting conditions of Sonazoid-enhanced US at a low and a high MI

Parameters	Low MI	High MI
Transducer	3.5 or 4.0-MHz convex transducer
Imaging mode	Coded phase inversion (A), Contrast pulse sequence (B), Pulse inversion harmonic (C), Amplitude modulation (D)	Coded harmonic angio (A)
MI	0.12-0.3 (average 0.2)	0.7-1.0 (average 0.8)
Frame rate	7-13 frames	2 -13 frames
Focus position	Bottom of the liver (A, D), Bottom of the lesion (B, C)	Bottom of the lesion (A)

A: LOGIQ 7 ultrasound system (GE Healthcare, Milwaukee, WI). Both imaging software programs consist of phase inversion harmonic and coded technology. These programs restrict signal components from tissues and emphasize signals from blood vessels; B: ACUSON Sequoia ultrasound system (Mochida Siemens Medical System, Tokyo, Japan); C: Aplio-XV ultrasound system (Toshiba, Tokyo, Japan); D: LOGIQ E9 ultrasound system (GE Healthcare, Milwaukee, WI).

Table 3 Comparison between Sonazoid-enhanced US images at low and high MI for evaluation of liver lesion vascularity

Parameters	Low MI		High MI
Vascular phase images
Tumor vessel image	Good	<	Very good
Tumor enhancement image	Good	<	Very good
Tumor enhancement image of the lesion located in deep portion or high echoic lesions	Poor	<<	Good
Real time image (frame rate)	Good (high frame rate)	>	Good to poor (high to low frame rate)
Late phase images
Scan starting time	At least 10 min	<	At least 5 min
Perfusion defect image of the lesion	Good	<	Very good
Perfusion defect images of the lesion located in deep portion or high echoic lesion	Poor	<<	Good
Real-time image (frame rate)	Very good (high frame rate)	>>	Poor (low frame rate)
Examination time	More than 10 min	<	More than 5 min
Injection volume of Sonazoid	Half or the volume recommended	<	Quarter or third of the volume recommended

Grades are classified as poor, good and very good. >> or >: Low MI is superior to high MI; << or <: High MI is superior to low MI.