A Standardized Technique for Ultrasound-MRI Fusion Imaging of the Carotid Artery for Vascular Assessment.

Abstract

Purpose: To describe a reproducible ultrasound-magnetic resonance imaging (MRI) fusion imaging technique developed for quantitative assessment of carotid wall strain and plaque morphology.

Methods: MRI volumes (Oblique T2 Cube) were imported into the Sequoia ultrasound system equipped with an electromagnetic tracking module. The fusion workflow aligned ultrasound and MRI coordinate spaces through anatomical landmark registration of the internal and external carotid arteries. Real-time B-mode and strain imaging were performed with a 10L4 transducer. The fused MRI volume provided spatial context for localization of plaque and intima-media regions. Following alignment, additional B-mode, color Doppler, and radiofrequency (RF) data were acquired on a Siemens S2000/S3000 system to match the imaging plane used during fusion.

Results: This workflow enabled consistent cross-modality localization of vascular features between MRI and ultrasound, improving repeatability of acquisitions. The S2000 acquisition step ensured that color Doppler and RF data corresponded to the same anatomical orientation defined during fusion.

Conclusion: This technique offers a practical framework for ultrasound-MRI fusion in carotid imaging and facilitates direct localization of similar structures across 2 imaging modalities. This approach also enables visualization across different systems with manual visual corroborations that, in this case, enabled standardized RF data collection for quantitative elastography research.