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A b s t r a c tBackground: Coronary computed tomography angiography (CCTA) is applied in a growing number of clinical indications. This imaging modality is often regarded as a surrogate of invasive coronary angiography (ICA). In this paper we evaluate the applicability of CCTA alone in the assessment of the SYNTAX score. Aim:To evaluate the feasibility of calculating the SYNTAX score (SXScore) using CCTA alone instead of ICA.Methods: Ninety consecutive patients with multivessel or left main (LM) coronary artery disease diagnosed with ICA, in whom prior CCTA scan was available, were included in a post-hoc analysis. First, the SXScore was calculated twice in ten-week intervals by two experienced observers using ICA for each patient. Then the SXScore was calculated twice using CCTA following the same regimen for each patient. Weighted kappa statistic was used to assess the intra-modality and inter-modality reproducibility of the SXScore.Results: Ninety patients, aged 63.8 ± 8.9 years, 60% male, 64.4% with two-vessel disease, and 35.6% with three-vessel or LM disease met the inclusion criteria. 287 lesions were identified by ICA and 280 by CCTA (p = 0.56). Median total SXScore was 11.5 (10.2-14.0) as calculated by ) by CCTA (p < 0.001), and the results were moderately correlated (R = 0.38). Inter-modality agreement between ICA and CCTA for SXScore tertiles was moderate (kappa = 0.40). The intra-modality reproducibility of ICA and CCTA for SXScore tertiles was 0.47 and 0.51, respectively. Conclusions:Inter-modality agreement between CCTA and ICA for calculation of SXSscore is moderate but only slightly worse than intra-modality reproducibility for angiographic alone evaluation. Most of the observed variability can be assigned to the characteristic of the SXScore itself, not to the choice of imaging method. However, the application of CCTA for the assessment of SXScore should be used cautiously.

Objectives: In the article we describe the new, high frequency, 20 MHz scanning/Doppler probe designed to measure the flow mediated dilation (FMD) and shear rate (SR) close to the radial artery wall.Methods: We compare two US scanning systems, standard vascular modality working below 12 MHz and high frequency 20 MHz system designed for FMD and SR measurements. Axial resolutions of both systems were compared by imaging of two closely spaced food plastic foils immersed in water and by measuring systolic/diastolic diameter changes in the radial artery. The sensitivities of Doppler modalities were also determined. The diagnostic potential of a high frequency system in measurements of FMD and SR was studied in vivo, in two groups of subjects, 12 healthy volunteers and 14 patients with stable coronary artery disease (CAD).Results: Over three times better axial resolution was demonstrated for a high frequency system. Also, the sensitivity of the external single transducer 20 MHz pulse Doppler proved to be over 20 dB better (in terms of a signal-to-noise ratio) than the pulse Doppler incorporated into the linear array. Statistically significant differences in FMD and FMD/SR values for healthy volunteers and CAD patients were confirmed, p-values < 0.05. The areas under Receiver Operating Characteristic (ROC) curves for FMD and FMD/SR for the prediction CAD had the values of 0.99 and 0.97, respectively.Conclusions: These results justify the usefulness of the designed high-frequency scanning system to determine the FMD and SR in the radial artery as predictors of coronary arterial disease.