Systems and methods for determining an abnormality in an elongated structure in a three dimensional medical image. One system includes an electronic processor. The electronic processor is configured to determine a centerline of the elongated structure in the three dimensional medical image and determine a plurality of two dimensional cross sections of the three dimensional medical image based on the centerline. For each two dimensional cross section of the plurality of two dimensional cross sections, the electronic processor is configured to convert the two dimensional cross section to polar coordinates, fit a line to the elongated structure in the two dimensional cross section converted to polar coordinates, and reconvert the two dimensional cross section to Cartesian coordinates.