International Circulation: There have been some concerns about using IVUS in the left main artery when associated with bifurcations. We know there can be some damage from a spasm or from thrombosis in the left main， as well as additional concern about putting extra devices in there. Is this an area you are concerned with?
　　Prof. Gregg Stone: No， not really. The use of IVUS in large coronary arteries is extremely safe. The areas where we will occasionally see incidents of spasm or dissection is usually when we are in small tiny vessels with the IVUS catheter. IVUS of the left main artery is critically important.
　　《国际循环》：一些人对于在左主干分叉病变中使用IVUS表示了担忧。我们知道在该部位导入某种装置时有可能会造成因血管痉挛或血栓形成而带来的损伤。您有这样的担心吗？
　　Gregg Stone：一点也不。在大的冠状动脉内使用IVUS非常安全。我们偶尔看到的血管痉挛或夹层多是发生于在微小血管内使用IUVS导管时的情况。在处理左主干病变时使用IVUS非常重要。
　　International Circulation: Do you have any specific standardized  method that you characterize lesions in the bifurcations? There are various methods used  to visualize， and it would be helpful to know if you have a specific method you use.
　　Prof. Gregg Stone: We tend to use the MEDINA classification. This classification is very simple and divides bifurcations into proximal bifurcation in the parent vessel， then the parent vessel distal to the bifurcation， then the side branch of the daughter vessel. You describe one point as to whether there is a greater than 50% degree of stenosis.
　　《国际循环》：在描述分叉病变特征时，您有哪些特殊的、标准化的方法？您使用的方法会对我们非常有帮助。
　　Prof. Gregg Stone：我们倾向于使用MEDINA分类法。这种方法非常简单，将分叉病变分为分叉近端的主支血管、分叉远端主支血管和分支血管的病变。你只需描述某一点是否存在狭窄超过50%的病变。
　　International Circulation: Have you tried other classifications? If so， what were the problems with them?
　　Prof. Gregg Stone: Many years ago， before the MEDINA classification came out we were using other classifications methods. Since the MEDINA classification came out it has been the most simple and straight forward. Other systems were just too complicated and too difficult to remember and did not provide any particularly interesting or important information you couldn’t see from visualization.
　　《国际循环》：您是否尝试使用过其他的分类方法？他们存在哪些问题？
　　Prof. Gregg Stone：许多年前我们曾经使用其他分类方法。但自从MEDINA分类法问世以后，已成为最简单、最直观的分类方法。其他的系统太过复杂，难以记忆，并且也不能提供影像学上不能看到的特别有价值的重要信息。