Information about local diameter variations as a response to the pulse flow in the human coronary arteries may indicate the development of atherosclerosis before this can be seen as a stenosis on coronary arteries may indicate the development of atherosclerosis before this can be seen as a stenosis on coronary angiograms. This paper describes the design of an image processing tool to measure this diameter variation from a sequence of digital coronary angiograms. If a blood vessel responds less elastically to the pulse flow, this may be an indication of atherosclerosis in an early stage. We have developed an image analysis and processing algorithm which is able after vessel segment selection by the user, to calculate automatically the vessel diameter variations from a standard sequence of digital angiograms. Several problems are treated. The periodic motion of the vessel segment in the consecutive frames is taken into account by tracking the vessel segment using a 2D logarithmic search to find the minimum in the mean absolute distance. A robust artery tracing algorithm has been implemented using graph searching techniques. The local diameter is determined by first resampling the image perpendicular to the found trace and afterwards performing edge detection using the Laplacian operator. This is repeated for all frames to show the local diameter variation of the artery segment as a function of time.
展开▼
