This will be a pilot study enrolling 75 participants. This is based off obtaining 80% power and a 90% rectangular confidence region for sensitivity and specificity using one-sided confidence limits, this corresponds to two 95% univariate confidence intervals (one for sensitivity and one for specificity). With 73 patients screened in total there will be 80% power to form a 90% rectangular confidence region around 90% sensitivity and 90% specificity, excluding sensitivities less than 69% and specificities less than 73%. We believe the sensitivities and specificities of both DSE with RTCE and cCTA will be within these confidence regions.