Measurements Of Common Carotid Artery Intima-Media Thickness In Ultrasound Images

The intima-media thickness(IMT) of common carotid artery(CCA) can serve as an important indicator for the assessment of cardiovascular diseases(CVDs). It’s of great value for the prevention and treatments of CVDs. In clinical practice, B mode ultrasound technology is used for CCA image acquisition, and computer-aided method is used for IMT measurements. In order to meet the requirements of large image datasets and high accuracy, proposing an automatic, fast and accurate approach for IMT measurements is the goal of this thesis.The approach proposed in this thesis can be divided into six cascaded steps:(1) the method of template-based matching is utilized for ROI extraction;(2) bilateral filtering is applied to remove noise in the extracted ROI;(3) LII boundary is estimated within the ROI using intensity threshold;(4) MAI is estimated based on the edge map and LII boundary;(5) the estimated boundaries are adjusted to their exact locations with improved dynamic programming;(6) IMT measurement and validation are carried out.After the design of the approach, the dataset consists of 100 ultrasound images was tested with the proposed approach. For each image, the IMT was measured with two different methods. The one measured with manual delineation served as the ground truth IMT, and the other measured with the automatic approach proposed in this thesis was the experimental IMT. Among the 93 correctly measured images, the correlation coefficient between ground truth IMT and experimental IMT was 0.9629, and the mean bias ? standard deviation between them was 0.0231 ? 0.0348 mm. The average processing time for each image was 0.32 seconds with MATLAB code under Windows XP on an Intel Core 2 Duo CPU E7500 @2.93 GHz. Compared with the representative researches in this field, the approach in this thesis achieved the goal of automatic, fast and accurate IMT measurements.