Lipid core plaque (LCP) in the coronary arteries is very common in acute coronary syndrome, but can often be found also in patients with stable angina. Lipid core plaque cannot be detected by angiography or intra-vascular ultrasound. Near infrared spectroscopy (NIRS) has the ability to identify chemicals in mixture. LipiScan, a catheter based NIRS coronary imaging system can detect intra-vascular LCP. This catheter has been shown to be able to identify LCP through blood in a prospective autopsy study, and that the LCP detection algorithm developed and validated on ex vivo data is applicable in vivo. The image generated by this system is called 'chemogram'. The catheter has also been tested successfully in a clinical study in the United States and Canada. Based on these studies the FDA approved the use of the LipiScan coronary imaging system. In CUMC, we have started to use this catheter to identify LCP, and have gained experience with its simple use.