Dual-Energy Computed Tomography-Enabled Material Separation in Diagnosing Left Atrial Appendage Thrombus

Area of Science:

• Medical Imaging
• Cardiovascular Imaging
• Radiology

Background:

• Left atrial appendage thrombi are a significant risk factor for stroke in patients with atrial fibrillation.
• Accurate detection of left atrial appendage thrombi is crucial for guiding therapeutic decisions, such as anticoagulation therapy and ablation procedures.
• Distinguishing thrombi from pectinate muscles can be challenging with conventional imaging techniques.

Purpose of the Study:

• To evaluate the clinical utility of material separation using dual-energy spectral computed tomography (DE-SCT) for detecting left atrial appendage thrombi.
• To assess the ability of DE-SCT to differentiate between left atrial appendage thrombi and pectinate muscles based on material decomposition.

Main Methods:

• A prospective study involving 24 patients undergoing atrial fibrillation ablation.
• Acquisition of computed tomograms using gemstone spectral imaging mode.
• Analysis of iodine and blood densities in the left atrial appendage cavities, pectinate muscles, and thrombi using material decomposition images at 70-keV monochromatic energy.

Main Results:

• On iodine-specific images, left atrial appendage thrombi and pectinate muscles appeared hypodense.
• On blood-specific images, thrombi and cavities showed higher attenuation compared to pectinate muscles.
• Quantitative analysis revealed significant differences in iodine and blood densities between thrombi, cavities, and pectinate muscles, enabling differentiation.

Conclusions:

• Dual-energy spectral computed tomography-enabled material separation is a novel approach for differentiating left atrial appendage thrombi from pectinate muscles.
• This technique holds potential clinical value in improving the detection of left atrial appendage thrombi.
• Further research is warranted to explore the broader applications of this technology in cardiovascular imaging.