Fig 6. Pearson correlation between the calculated stenosis area (based upon the narrowest diameter) and the measured cross-sectional VT area of stenosis (mm2). The calculated area showed a trend of underestimating the area in comparison to the measured area. This trend is not surprising, because the calculated area is based upon the narrowest stenosis, which does not account for noncircular stenoses. Nonetheless, there was excellent correlation between these 2 methods of area quantification (correlation coefficient = 0.87; n = 176).