The median total volume of contrast was 64.5 ml ( interquartile range [ IQR ] : 42.8 to 97.0 ml ; minimum , 19 ml ; maximum , 170 ml ) in the angiography-guided group versus 20.0 ml ( IQR : 12.5 to 30.0 ml ; minimum , 3 ml ; maximum , 54ml ) in the IVUS-guided group ( p < 0.001 ) .