Optical Imaging Measurement of Intravascular Solution Efficacy Trial

Iodinated contrast is the current gold standard for infrainguinal angiography imaging in patients without renal insufficiency and has also been used with intravascular Optical Coherence Tomography (iOCT) to improve image quality in human coronary arteries as well as carotid arteries. The current debate in the literature for iOCT medium is between iodinated contrast and dextran and CO2 may offer a superior method of iOCT imaging during lower extremity occlusive disease interventions. The investigators hypothesize that the CO2 medium injection during iOCT data acquisition is feasible and will produce at least the same quality of imaging as that obtained with contrast or dextran without causing the problems of volume overload and renal toxicity seen with the two latter mediums. Primary Outcomes Measured * Quality: Cumulative number of clear image frame (CIF) through the entire 54mm length segment. * Quantitative: Calculations of the area and diameter of each segment will be measured to determine if index of refraction has any effect between the three mediums to be tested. The investigators expect to find little difference between all three iOCT mediums and hope to conclude that CO2 offers a superior side effect profile for iOCT imaging in the lower extremity arterial system.