Background StentBoost (SB) is a novel angiographic technique which can enhance stent visualization and improve detection of inadequate stent expansion. Studies of SB that compare it with intravascular ultrasound (IVUS), which is the current gold standard for detection of stent underexpansion, remain inadequate. This study aimed to test the correlation of IVUS and SB, and to evaluate the effect of SB guiding the stent postdilatation.Methods From March 2009 to June 2010, 52 patients were analyzed using quantitative coronary angiography (QCA),IVUS, and SB. They included 37 patients (54 stents) with postdilatation and 15 patients (21 stents) without postdilatation.Correlations of stent diameter between the three modalities were determined.Results The minimum diameter, maximum diameter and average diameter of postdilatation obtained by QCA, IVUS,SB were significantly larger than that of poststenting, and the ratio (maximum stent diameter (MaxLD)-minimum stent diameter (MinLD))/MaxLD of postdilatation was smaller. Correlations of MinLD were the highest between IVUS and SB (r=0.979, P ＜0.0001) when compared with QCA and SB (r=0.973, P ＜0.0001), and QCA and IVUS (r=0.964, P ＜0.0001).Conclusions SB has superior correlations for stent expansion measured by IVUS when compared with QCA. In addition, there is an important advantage for SB in guiding the stent postdilatation.