血管内超声（IVUS）是一个非常好的工具，在大约25%的病例中我会应用IVUS。如果处理左主干病变并想知道支架是否成功放置，我会应用IVUS确定；如果遇到有严重钙化病变的糖尿病患者，为了更好的了解病变以便置入支架，我会使用IVUS；这可以扩展到更复杂的问题，如发现血栓形成的根源。当某些问题应用血管造影难以解决时，IVUS可能有所帮助。
　　在评价冠心病患者斑块体积以及血管狭窄程度方面，IVUS和冠状动脉CT这两种技术不存在任何程度的竞争。对患者进行诊断或者判断病变的范围，可以使用冠状动脉CT。而要想知道病变的类型，决定应该采用何种方法治疗，则推荐使用IVUS。
　　根据放射防护手册，如果患者接受了超过既定剂量的辐射，则有相应的处理策略以确保患者免受射线的不利影响。介入心脏病学医师在介入手术过程中应严格遵守操作规程，定期检查机器设备以保证放射线暴露在规定范围，及时发现机器的潜在故障。
　　International Circulation: Previous studies have shown that event-free survival rate after PCI is increased by IVUS guidance. Is it necessary for common use or only for high-risk patients?
　　Prof. Gérald Barbeau: I think IVUS is a wonderful tool and personally I use it in about 25% of my cases. Basically， if I do a left main and I want to know that my stent is perfectly upheld， then I will use an IVUS to ascertain this. If I am presented with a diabetic patient with a heavily calcified lesion and I would like to implant a stent， in order to understand the lesion better I will need to use IVUS. This can be extended for more complicated problems such as finding out the source of thrombosis. If there is any problem not resolved using an angiogram， then IVUS can be helpful also.
　　International Circulation: IVUS is regarded as the “gold standard” for coronary artery examination. However， coronary CT is more popular in China due to its accessibility. How do you appraise the ability of IVUS and CT to detect plaque volume and luminal narrowing of the coronary artery?
　　Prof. Gérald Barbeau: We do not look extensively at the plaque volume mainly because we do not use CT. This is because CT is much more complicated than IVUS. I do not think there is any degree of competition between these two procedures. If you want a diagnosis of whether the patient has a disease or not or whether there is an extension of the lesion， then the CT is available. If you， however， want to know what type of lesion it is and how you should treat it， then an IVUS is much more recommended.
　　International Circulation: What do you think should be the best policy to protect patients and physicians from radiation?
　　Prof. Gérald Barbeau: The X-ray guidebook recommends that if a patient receives more than the specified amount of radiation， there is a policy of following the patient to make sure there are no detrimental effects from the radiation. For interventional cardiologists， we have regular courses regarding this batch limit and we have to follow these protocols thoroughly. The batch will tell us where we are with the radiation and if we are either too high or too low， then people will ask what directions to take. However， it is mandatory that we use it. The machines are checked and maintained on a regular basis to ensure that radiation level exposure is within safe levels and we have regular courses which teach us to spot any potential faults in the machines.
　　Gérald Barbeau教授：介入心脏病学专家，加拿大Laval医院心脏科副教授，在世界上率先开展经桡动脉冠状动脉造影检查，并首先设计出桡动脉专用介入导管，解决了导管到位困难和导引导管支撑力不足的弊端。