All patients in this study will undergo standard cardiac catheterization and intervention as directed by their treating physician. In this research, the researchers will analyze imaging data that will be collected during the procedure. This includes the angiography (all patients), intravascular ultrasound (in the patients that the operator determines its need for use as part of the procedure), and imaging from the LipiScan catheter (all patients). The LipiScan catheter is approved by the FDA for intravascular detection of fat in the blood vessel, and will be used to detect the fat composition of the blockage. This catheter, detects whether the blockage is composed of fat and is soft, or is fibrous and hard. In this study we are going to try to identify the type of blockages that are associated with branching points, and to learn whether soft and fat containing blockages are associated with shifting or movement of the blockage material into the side branch. The information learned from this study may help interventional cardiologists in the future to better plan their interventional techniques and strategy and to perform safer and more successful procedures.