Abstract
In this work, a hybrid approach for the multimodal registration of carotid magnetic resonance and ultrasound images is described. Multimodal registration is vital for integrating or fusing complementary information from different sources into a composite form. It will provide synergistic information about the objects under examination and thus, help in the assessment of carotid artery disease. The proposed hybrid approach combines the strengths of feature- based and intensity-based registration approaches to attain more precise registration in challenging problems. The feature- based iterative closest point algorithm has been used to provide the initial alignment of images which was traditionally done by manual operators. Subsequently, the intensity-based approach uses rigid-body model, to describe the global motion and non-rigid free-form deformation model based on B-splines, to describe the local motion of the carotid arteries. The normalized mutual information metric assessed the similarity in both rigid and non-rigid transformation models. Quantitative and qualitative evaluations of the proposed hybrid technique have also been presented. The results showed that the proposed hybrid registration method achieved a target registration error (TRE) of 0.1094 mm which is significantly less by 79.9% as compared to TRE of 0.5444 mm achieved using pure geometric method and by 73.4% in comparison to TRE of 0.4121 mm achieved using the composition of rigid geometric and iconic approaches.
Highlights
Direct visualization of carotid atherosclerotic plaques provides useful insights on the natural history of atherosclerotic disease and aids in selecting appropriate treatments
The accuracy of proposed registration method is assessed using a geometric measure called target registration error (TRE), which is defined as the displacement between two corresponding points after registration [23]
Multimodality registration of MR and US data is essential for accurately correlating the findings obtained by both modalities for the purpose of diagnosis, treatment and basic sciences
Summary
Direct visualization of carotid atherosclerotic plaques provides useful insights on the natural history of atherosclerotic disease and aids in selecting appropriate treatments. Noninvasive MRI has great potential to enable characterization of atherosclerotic plaque composition and morphology, which helps to assess plaque vulnerability. It differentiates plaque components on the basis of biophysical and biochemical parameters such as chemical composition and concentration, water content, physical state, molecular motion or diffusion [1]. Multispectral carotid MR imaging is able to characterize all major plaque components: active inflammation, thin cap with large lipid-necrotic core, endothelial denudation with superficial platelet aggregation, fissured plaque and stenosis by depicting particular combinations of signal intensities of each component on images obtained with different contrast weightings [2]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
