Snakes based segmentation of the common carotid artery intima media

Abstract

Ultrasound measurements of the human carotid artery walls are conventionally obtained by manually tracing interfaces between tissue layers. In this study we present a snakes segmentation technique for detecting the intima-media layer of the far wall of the common carotid artery (CCA) in longitudinal ultrasound images, by applying snakes, after normalization, speckle reduction, and normalization and speckle reduction. The proposed technique utilizes an improved snake initialization method, and an improved validation of the segmentation method. We have tested and clinically validated the segmentation technique on 100 longitudinal ultrasound images of the carotid artery based on manual measurements by two vascular experts, and a set of different evaluation criteria based on statistical measures and univariate statistical analysis. The results showed that there was no significant difference between all the snakes segmentation measurements and the manual measurements. For the normalized despeckled images, better snakes segmentation results with an intra-observer error of 0.08, a coefficient of variation of 12.5%, best Bland-Altman plot with smaller differences between experts (0.01, 0.09 for Expert1 and Expert 2, respectively), and a Hausdorff distance of 5.2, were obtained. Therefore, the pre-processing of ultrasound images of the carotid artery with normalization and speckle reduction, followed by the snakes segmentation algorithm can be used successfully in the measurement of IMT complementing the manual measurements. The present results are an expansion of data published earlier as an extended abstract in IFMBE Proceedings (Loizou et al. IEEE Int X Mediterr Conf Medicon Med Biol Eng POS-03 499:1-4, 2004).

An integrated system for the complete segmentation of the common carotid artery bifurcation in ultrasound images

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Ultra-sonografia do fígado, aparelho renal e reprodutivo da jibóia (Boa constrictor)

“…A combinação de um comportamento tranqüilo em cativeiro, associado ao tamanho e seu padrão estético, tem influenciado no aumento da procura comercial destes animais. Esse fato tem aumentado a necessidade de um maior contingente de informações em relação a esta espécie (Loizou et al 2007).…”

Medical Decision Support System of Common Carotid Artery Using Image Mining and Dual Snake Segmentation Procedure

“…Before processing an image into an application, the quality of an image has been improved by using the pre-processing techniques 3,4 . To get a new brightness value in the output image, it uses a pixel value of a neighborhood values an input image.…”