Junga Baek, Abstract Co-Author: Nothing to Disclose

Helen Hong PhD, Presenter: Nothing to Disclose

Our method can be used to diagnose coronary artery diseases and establish a heart treatment planning.

X-ray angiography is a common modality for cardiologists to assess the severity of vessel narrowing or stenosis during percutaneous coronary interventions. For quantitative analysis of coronary arteries in X-ray angiography, an accurate detection of a set of major arteries is a crucial process. However, there are difficulties in detecting coronary arteries in X-ray angiogram due to poor signal-to-noise ratio, vessel overlap, superimposition with various anatomical structures, irregular distribution of the contrast medium and vessel tapering in bifurcated lesions. In this paper, we propose an accurate method for detecting contours of single and bifurcated vessels and calculating reference vessel diameter.

Our adaptive contrast stretching reduces the irregular distribution of the contrast medium and the gradual density changes in vessel contour. Our contour detection allows the absolute vessel diameter to accurately calculate inspite of vessel overlap, superimposition with various anatomical structures. Our reference vessel diameter calculation estimates the percentage area of stenosis

Our method has been applied to twenty patients with coronary occlusion or stenosis in X-ray angiogram which has a matrix size of 512 x 512 pixels (8bits). For catheter calibration, a catheter contour is extracted by edge detection and mode of candidate catheter diameter. An initial vessel area is segmented by region growing and the vessel centerline is extracted by thinning and pruning. For bifurcated vessel analysis, a bifurcated polygon is defined in a bifurcated lesion and a bifurcated point is detected by matching of the bifurcation patterns from vessel centerline. The vessel contour points are detected by adaptive contrast stretching and edge detection. An absolute vessel diameter is obtained from the diameter of the detected vessel and a reference vessel diameter is determined from the edges of the healthy part of neighbor vessel. Our method was visually assessed and compared with CAAS QCA software.

Baek, J, Hong, H, Automatic Contour Detection and Reference Diameter Calculation of Single and Bifurcated Vessels in X-ray Angiography for Quantitative Coronary Analysis.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12035389.html