Figure 4

A freehand region of interest (ROI) was drawn around the margin of the plaque using an electronic-cursor, avoiding the lumen and surrounding tissue.
Perfusion indices such as peak intensity (PI) and baseline intensity (BI) were calculated by the ACQ software. Enhanced intensity (EI, EI = PI − BI) was reduced from 8.02 dB at baseline (A) to 7.88 dB after treatment (B).