[Quantitative evaluation of deformity of the iliac artery during extension and flexion of the hip joint: three-dimensional evaluation using MDCT].

We performed CT-angiography twice, first hip joint extension, followed by second flexion. Using vessel analysis software, we placed several points of interest at equal intervals on the center line of the iliac artery, from the bifurcation to the femoral artery inguinal portion, and recorded the their three-dimensional coordinates. We also marked the circumference, which passes by three points that add the respective next point and prior point to each reference point. This curvature (the inverse number of the radius) was utilized as the index that displays crookedness. This method was able to estimate quantitatively the grade of crookedness, and, by comparing an equidistant point from the bifurcation, to show the changes in grade at flexion of the hip joint.