Coronary calcium quantification using contrast-enhanced dual-energy computed tomography scans

Area of Science:

• Medical Imaging
• Cardiovascular Imaging
• Radiology

Background:

• Conventional cardiac CT requires separate noncontrast scans for calcium quantification and contrast-enhanced scans for angiography.
• Distinguishing coronary calcium from contrast material on enhanced images is challenging.

Purpose of the Study:

• To evaluate dual-energy computed tomography (DECT) for direct coronary calcium burden measurement during contrast-enhanced imaging.
• To eliminate the need for a separate noncontrast scan in cardiac CT examinations.

Main Methods:

• Developed virtual noncontrast images from DECT data to resolve calcium-contrast ambiguity.
• Determined a 130 HU threshold for DECT calcium scoring using linear and logistic regression analyses.
• Validated the method with an in vitro phantom study and an in vivo prospective patient study.

Main Results:

• The logistic regression model identified a threshold accurately detecting calcium's risk for adverse coronary events (2.45% error rate).
• DECT-derived calcium mass and volume scores strongly correlated with conventional Agatston and volume scores (r = 0.98, p < 0.001).

Conclusions:

• DECT enables accurate coronary calcium quantification from contrast-enhanced images.
• A single DECT contrast-enhanced scan can replace two conventional scans for both calcium scoring and coronary angiography, improving efficiency.