Echo ultrasound measurement of lumen size in aortic aneurysm

Aneurysm of the (descending) aorta is characterized by modified wall properties, and ballooned area filled by a thrombus. The study of the wall and thrombus cross sectional distension due to pressure wave is important as a way of assessing the degradation of the wall mechanical properties and the hazard of rapture. Ultrasound imaging is used here to study the thrombus distension, requiring its segmentation within the image. Since echoes from the lumen and embolism produce similar patterns and speckle noise, a specific method for identifying the lumen-embolism border was developed. The method is based on filtering by a modified Canny-Deriche edge detector and then on minimization of an energy function based on 5 parts. The method is robust enough to track the lumen and total arterial cross sectional area changes during the cardiac cycle. In five patients accuracy of ~85% was achieved in the sequences of images