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Updated: Feb 11, 2026
Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans
Published on: August 28, 2018
Advanced analyses of computed tomography coronary angiography can help discriminate ischemic lesions
Jun-Mei Zhang1, Dongsi Shuang2, Lohendran Baskaran3
1National Heart Center Singapore, 5 Hospital Drive, 169609, Singapore; Duke-NUS Medical School, 8 College Rd, 169857, Singapore.
Insights
Computed tomography coronary angiography (CTCA) analysis of plaque volume and napkin-ring sign, alongside numerical simulations for FFRB, significantly improves the detection of ischemic coronary lesions compared to diameter stenosis alone.
Area of Science:
- Cardiovascular Imaging
- Computational Fluid Dynamics
- Biomedical Engineering
Background:
- Computed tomography coronary angiography (CTCA) facilitates plaque characterization and non-invasive fractional flow reserve (FFR) calculation.
- Analyzing CTCA-derived parameters aids in understanding their association with myocardial ischemia.
Purpose of the Study:
- To evaluate the association of various CTCA-derived anatomical, plaque, and hemodynamic parameters with ischemia.
- To determine the predictive value of these parameters, including normalized plaque volume (NP Vol) and napkin-ring (NR) sign, in identifying obstructive coronary lesions.
Main Methods:
- CTCA and invasive FFR were performed on 49 patients (61 lesions).
- Image processing quantified lesion length, minimum lumen area, plaque characteristics (volume, NP Vol, NR sign), and hemodynamic parameters (FFRB).
- Ischemia was defined as FFR ≤ 0.8; obstructive lesions had diameter stenosis (DS) ≥ 50%.
Main Results:
- Plaque burden and volume were inversely correlated with FFR.
- Multivariable analysis identified NP Vol and NR Sign as significant plaque predictors, and FFRB as a strong hemodynamic predictor of ischemia.
- The area under the curve (AUC) for predicting ischemia increased from 0.70 (DS alone) to 0.81 (DS, NP Vol, NR Sign) and 0.93 (DS, NP Vol, NR Sign, FFRB).
Conclusions:
- Normalized plaque volume and napkin-ring sign from CTCA plaque analysis significantly enhance the discrimination of ischemic lesions.
- FFRB derived from numerical simulations on CTCA images further improves diagnostic accuracy.
- Combined CTCA parameters offer superior detection of ischemia compared to DS alone.
Background:
Computed tomography coronary angiography (CTCA) image analysis enables plaque characterization and non-invasive fractional flow reserve (FFR) calculation. We analyzed various parameters derived from CTCA images and evaluated their associations with ischemia.
Methods:
49 (61 lesions) patients underwent CTCA and invasive FFR. Lesions with diameter stenosis (DS) ≥ 50% were considered obstructive. CTCA image processing incorporating analytical and numerical methods were used to quantify anatomical parameters of lesion length (LL) and minimum lumen area (MLA); plaque characteristic parameters of plaque volume, low attenuation plaque (LAP) volume, dense calcium volume (DCV), normalized plaque volume (NP Vol), plaque burden, eccentricity index and napkin-ring (NR) sign; and hemodynamic parameters of resistance index, stenosis flow reserve (SFR) and FFRB. Ischemia was defined as FFR ≤ 0.8.
Results:
Plaque burden and plaque volume were inversely related to FFR. Multivariable logistic regression analysis identified the best anatomical, plaque and hemodynamic predictors, respectively, as DS (≥50% vs <50%; OR: 8.0; 95% CI: 1.6-39.4), normalized plaque volume (NP Vol) (≥4.3 vs <4.3; OR: 3.9; 95% CI: 1.1-14.0) and NR Sign (0 vs 1; OR: 13.6; 95% CI: 1.3-146.1), and FFRB (≤0.8 vs >0.8; OR: 44.4; 95% CI: 8.8-224.8). AUC increased from 0.70 with DS as the sole predictor to 0.81 after adding NP Vol and NR Sign; further addition of FFRB increased AUC to 0.93.
Conclusion:
Normalized plaque volume, napkin-ring derived from plaque analysis, and FFRB from numerical simulations on CTCA images substantially improved discrimination of ischemic lesions, compared to assessment by DS alone.
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