The purpose of the Metricath Gemini System is to pre-dilate the target treatment area, take arterial lumen measurements in a native section of artery or within the deployed stent and perform further dilation of the deployed stent if required. In this manner, the Metricath Gemini System can assist the Interventionalist by providing arterial measurements prior to stenting, performing pre-stenting angioplasty, taking within stent measurements to help determine if the stent is fully deployed, and by performing post-stenting dilations to further dilate the stent if required.