Intermediate MI (e.g. 0.1-0.3) is feasible as a real-time technique. There is more bubble destruction than with low MI imaging, but the advantage is that the stronger non-linear oscillations generated by the microbubbles (since they resonate more with increasing MI) yields a stronger acoustic signal. Low MI imaging (<0.1) generates virtually no tissue signal, which is good in most cases but sometimes the returning signals are too weak and thus subtle structural abnormalities may be missed.
Consequently, for LV opacification and assessment of LV structure, we recommend intermediate MI imaging (0.1-0.3).