 The goal of this study is to investigate the exposure dose reduction provided by ROI imaging to patients and interventionists undergoing catheterization and to examine the feasibility of using the ROI attenuator in routine clinical practice for future integration into commercial x-ray imaging systems. The aim is to obtain exposure dose data and cardiac angiography images from subjects undergoing routine interventional procedures performed with and without ROI attenuation experimental and control groups, respectively. For the experimental group, the interventionists performing the procedure will determine the appropriate application of the ROI attenuator and the duration of its use on specific patient lesions. An internal pilot study will be initially conducted on approximately 30 patients 15 per group to obtain estimates on patient and operator dose reduction and variability. The on-going clinical trial will then be performed on an additional 40 patients where the final protocol procedures and recruitment will be refined based on results from the pilot study. 