RESUMO
Measurements of arterial diameter during the cardiac cycle are increasingly used to study the mechanical properties of the arterial wall and changes associated with disease. In this paper, diastolic and systolic diameters of the carotid arteries were estimated from ultrasound imaging using the following three different procedures: a/ B-mode imaging with region tracking and block-matching, b/ M-mode imaging with automated edge detection and c/ automatic segmentation of the arterial lumen at diastole and systole using the Hough transform. Transverse images of the carotid artery were used, in which the arterial lumen has an almost circular appearance. The values for systolic and diastolic diameters estimated with the Hough transform, 0.69±0.04 and 0.61±0.06, respectively, were closer to those estimated with B-mode and motion tracking, 0.75±0.07 and 0.67±0.09. A large difference was found for a subject with an atherosclerotic vessel wall. It is concluded that the Hough transform can be efficiently used to automatically segment healthy arterial wall lumen from B-mode ultrasound images of the carotid artery, assuming a circular shape. In atherosclerotic vessel walls the assumption for circular shape may no longer be valid, and thus the use of an elliptical shape may be more appropriate.
