This paper describes a method for automatically determining the outline of the left ventricle(LV) from its angiograms. It is shown that when the histograms of the pictures are relatively narrow, some of the existing techniques are unsuitable for boundary detection. It is further shown that by appropriate partitioning of the pictures, an existing automatic thresholding technique can be applied to these pictures. The discontinuities that occur in the thresholded pictures are eliminated by the use of suitable 2-D filters. The techniques thus developed are applied to two particular LV angiograms at end-systole and at end -diastole.
G.M. X. Fernando,
D. M. Monro,
"Variable Thresholding Applied To Angiography", Proc. SPIE 0375, Medical Imaging and Image Interpretation, (1 November 1982); doi: 10.1117/12.934615; https://doi.org/10.1117/12.934615