A new approach for the automated definition of path lines in digitized coronary angiograms.

For the quantitative analysis of a coronary segment from a coronary (cine)angiogram, an initial path line is required which functions as a model for the subsequent automated contour detection. For on-line applications, a new method for the automated definition of arterial path lines has been developed. Required user-interaction consists of the manual definition of a beginning and an endpoint of the arterial segment to be analyzed. The method is based on a combination of a beam tracer and a box technique. A validation study was performed on 47 non obstructed arteries of various lengths and diameters, and on 56 arterial segments with obstructions (up to 86 percent diameter stenosis). In 89% of the cases an acceptable path line was found after the first iteration; the success score increased to 99%, if a simple manual correction was allowed (2 iterations). The method is extremely fast: the overall average search time for the first iteration was 266 ms, for the second iteration 211 ms. Therefore, it may be concluded that this new technique for the automated definition of arterial path lines is extremely suitable for on-line applications.