At the ostium and the mid-point of the proximal LAD, the lumen cross-sectional areas were respectively 14.5 ± 3.6 and 14.4 ± 3.6 mm2, the (EEM) cross-sectional areas were respectively 18.3 ± 3.1 and 17.8 ± 3.7 mm2, the midwall diameters were the same of 4.5 ± 0.5 mm. Conclusion: IVUS is superior than coronary angiography in detection of the atherosclerotic plaques.