Comparative Reproducibility Analysis of Thoracic Aorta Morphometric Parameters According to Computed Tomography and Magnetic Resonance Angiography

Abstract

Objective: to compare intra- and inter-operator reproducibility of thoracic aorta (ThAo) morphometric parameters, calculated by multislice computed tomography (MSCT) and magnetic resonance imaging (MRI). Material and methods . The prospective study included 20 patients with ascending aorta (AAo) dilatation (≥45 mm). All patients underwent MSCT- and MRI-angiography in electrocardiogram-gated mode. Mean diameter (Dmean) and cross-sectional area (CSA) were measured at different ThAo levels in the systole and diastole along the inner contour of the vessel. All measurements were performed by two radiologists. Each of them took measurements twice at an interval of at least 1 month. The reproducibility of repeated measurements was studied using intraclass correlation coefficient. Results. The analysis of the systolic frame revealed significant differences between the methodsfor measuring Dmean (MRI: 42.5 (41.0–47.8) mm; MSCT: 37.7 (34.7–40.3) mm; p = 0.003) and CSA at the level of the sinotubular junction (MRI: 14.8 (12.7–17.9) cm 2 ; MSCT: 11.4 (10.3–13.3) cm 2 ; p = 0.009), AAo CSA(MRI: 17.6 (14.6–20.8) cm 2 ; MSCT: 19.6 (16.7–21.5) cm 2 ; p = 0.035) and Dmean at the level proximal to left subclavian artery (LSA) (MRI: 31.5 (31.0–34.0) mm; MSCT: 31.7 (27.3–32.9) mm; p = 0.041). For the diastolic frame, significant differences between the methods were observed when measuring AAo CSA (MRI: 17.0 (14.5–19.7) cm 2 ; MSCT: 19.7 (15.3–21.8) cm 2 ; p = 0.025), Dmean (MRI: 30.5 (29.3–32.8) mm; MSCT: 29.8 (27.1–31.3) mm; p = 0.05) and CSA at the level proximal to LSA (MRI: 7.5 (6.9–7.9) cm 2 ; MSCT: 7.4 (5.9–7.8) cm 2 ; p = 0.007), as well as CSA at the left atrium level (MRI: 4.9 (4.2–5.0) cm 2 ; MSCT: 5.1 (4.67–5.5) cm 2 ; p = 0.042). For MSCT-angiography, good intra- and inter-operator reproducibility of measurements at all ThAo levels was obtained. For MRI-angiography, there was a strong intra- and interoperator variability in determining Dmean and CSA at the levels of aortic arch and descending aorta. Conclusion. Aortic cross-sectional area showed the best intra- and inter-operator reproducibility and comparability of measurements between MSCT- and MRI-angiography