Calcium evaluation using coronary computed tomography in combination with optical coherence tomography.

Area of Science:

• Cardiovascular Imaging
• Interventional Cardiology
• Medical Imaging Analysis

Background:

• Optical coherence tomography (OCT) is crucial for assessing coronary calcium thickness, guiding stent expansion.
• OCT's limited penetration depth leads to underestimation of coronary calcium severity.
• Accurate calcification assessment is vital for successful percutaneous coronary intervention (PCI).

Purpose of the Study:

• To evaluate and compare coronary computed tomography (CT) and OCT imaging for assessing coronary artery calcification.
• To determine the extent to which OCT underestimates calcium severity compared to CT.
• To explore the complementary roles of CT and OCT in pre-procedural PCI planning.

Main Methods:

• Co-registration and analysis of 1811 paired cross-sectional CT and OCT images from 25 left anterior descending arteries.
• Quantification of calcification presence, angle, thickness, and density in both imaging modalities.
• Comparison of calcium characteristics between images where calcification was detected by OCT versus those where it was not.

Main Results:

• Calcification was undetectable by OCT in 14.1% of corresponding CT images due to penetration limits.
• In OCT-detectable images, maximum calcium thickness was missed in 49.1% compared to CT.
• CT demonstrated significantly greater calcium angle, thickness, and density in slices undetected by OCT.
• Excellent correlation found between CT and OCT for calcium angle (R=0.82).
• OCT calcium thickness correlated better with CT maximum density (R=0.73) than CT thickness (R=0.61).

Conclusions:

• Cross-sectional CT imaging offers superior pre-procedural assessment of coronary calcium morphology and severity.
• CT can effectively complement OCT by providing information on calcium severity missed due to OCT's penetration limitations.
• Integrating CT and OCT data may enhance PCI strategy and outcomes.