Fig. 2.
Visual demonstration of parameters extracted from a vessel centerline for VTI computation. (a) Angle between a line tangent to the centerline and a reference axis for the first centerline point. (b) Tangent lines for points along the centerline. SD of angles between each tangent line and the reference axis was computed. (c) Critical points (red circles) were determined based on changes in sign of slope of the tangent lines. (d) Magnitude of curve as ratio of arch length (LA) to the chord length (LC) between pairs of inflection points including centerline end points (red squares).