Patent Document ID: 9256940
Application ID: 14343132
Patent Status: 1

Claim One:
1. A C-arm x-ray imaging apparatus for processing a 2D projection image taken of a tubular structure comprising a first tube and a second tube, the second tube branching off from the first tube at an opening in a sidewall of the first tube, the image taken whilst a contrast agent carrying fluid is residing in the tubular structure, the imaging apparatus comprising: a processing unit configured to select an initial projection image taken along a projection axis, the first tube and the second tube, when viewed along the projection axis, overlapping to form an overlap region in the initial projection image; a segmenter configured to segment the overlap region in the initial projection image, the processing unit being further configured to establish, based on the segmentation of the initial projection image, an estimate for the position in the projection image of the sidewall opening; an output unit configured to display a marker for the estimated sidewall opening position thereby providing a visual representation for the position in the initial projection image of the sidewall opening; and an intensity detector configured to detect inside or at a boundary of the overlap region an intensity drop, thereby establishing the position where the drop occurs as the estimate for the position of the first tube's sidewall opening.