Accuracy of CT-derived anomalous coronary arteries anatomy versus 3D-reconstructed IVUS in-vivo reference
A W Stark, A Mokhtari, R Kakizaki, M R Bigler, M Ilic, A Ashraf, K Stoyanov, C Ryffel, L Raeber, I Shiri, C GraeniAbstract
Background
In anomalous aortic origin of a coronary artery (AAOCA), coronary CT angiography (CCTA) is the primary tool for anatomical assessment. However, CCTA measurements lack validation against a high-resolution in-vivo standard.
Objectives
To assess CCTA reliability for lumen dimensions and intramural length (IML) in AAOCA, and to validate these against a three-dimensionally reconstructed intravascular ultrasound (3D-IVUS) reference standard using additionally three IML methodologies.
Methods
Fifty consecutive AAOCA patients underwent both CCTA and invasive IVUS. A 3D-IVUS reference standard was constructed and its geometric reproducibility assessed. CCTA reliability and agreement with 3D-IVUS were evaluated for ostial dimensions, position-dependent minimal lumen area (MLA), and IML, measured by interluminal space (ILS), elliptic ratio, and pericoronary fat sign.
Results
3D-IVUS reference standard showed excellent geometric reproducibility (median point-wise distance 0.21 mm, 95%CI 0.08–0.44 mm) and high intrareader reliability (ICC 0.91–0.97). CCTA intra- and inter-reader reliability was good-to-excellent for ostial parameters and ILS-derived IML (ICC 0.83–0.93), but poor for MLA position (ICC 0.32–0.53). Against 3D-IVUS, CCTA ostial dimensions correlated strongly (r=0.71, p<0.001) with minimal bias, and ILS-derived IML showed acceptable agreement (r=0.64; bias +4.8%), while the fat sign substantially overestimated length (+94.7%).
Conclusions
When using 3D-IVUS serving as an in vivo reference standard for precise coronary anatomy assessment in AAOCA, shows that CCTA reliably quantifies [GC1] ostial dimensions and IML using the ILS method especially for larger vessel dimensions, supporting its role as a non-invasive classification tool, but remains unreliable for MLA position-dependent measurements and submillimeter precision measurements.For image description, please refer to the figure legend and surrounding text.