Automatic centerline extraction of coronary arteries in coronary computed tomographic angiography

Coronary computed tomographic angiography (CCTA) is a non-invasive imaging modality for the visualization of the heart and coronary arteries. To fully exploit the potential of the CCTA datasets and apply it in clinical practice, an automated coronary artery extraction approach is needed. The purpose of this paper is to present and validate a fully automatic centerline extraction algorithm for coronary arteries in CCTA images. The algorithm is based on an improved version of Frangi’s vesselness filter which removes unwanted step-edge responses at the boundaries of the cardiac chambers. Building upon this new vesselness filter, the coronary artery extraction pipeline extracts the centerlines of main branches as well as side-branches automatically. This algorithm was first evaluated with a standardized evaluation framework named Rotterdam Coronary Artery Algorithm Evaluation Framework used in the MICCAI Coronary Artery Tracking challenge 2008 (CAT08). It includes 128 reference centerlines which were manually delineated. The average overlap and accuracy measures of our method were 93.7% and 0.30 mm, respectively, which ranked at the 1st and 3rd place compared to five other automatic methods presented in the CAT08. Secondly, in 50 clinical datasets, a total of 100 reference centerlines were generated from lumen contours in the transversal planes which were manually corrected by an expert from the cardiology department. In this evaluation, the average overlap and accuracy were 96.1% and 0.33 mm, respectively. The entire processing time for one dataset is less than 2 min on a standard desktop computer. In conclusion, our newly developed automatic approach can extract coronary arteries in CCTA images with excellent performances in extraction ability and accuracy

Diagnostic performance of transluminal attenuation gradient and fractional flow reserve by coronary computed tomographic angiography (FFRCT) compared to invasive FFR: a sub-group analysis from the DISCOVER-FLOW and DeFACTO studies

Although coronary computed tomographic angiography (CCTA) has been a robust diagnostic tool to identify anatomical significance of coronary artery disease (CAD), the utility of CCTA to assess hemodynamic significance of CAD remains unclear. We investigated the diagnostic performance of transluminal attenuation gradient (TAG) and fractional flow reserve derived from CCTA (FFR ) to predict lesion-specific ischemia by invasive FFR. We identified 103 patients with suspected or known CAD enrolled from the DISCOVER-FLOW and DeFACTO studies who underwent invasive coronary angiography with FFR and high quality ≥64-slice CCTA. Diagnostic performance for predicting abnormal invasive FFR (≤0.80) was assessed for TAG [≤−1.1 HU/mm by the area under the curve (AUC) by receiver-operating characteristic curve analysis (ROC)], FFR (≤0.80), and CCTA stenosis (≥50 %). On a per-vessel analysis (n = 146), 52 vessels (35.6 %) had ischemia by invasive FFR. The sensitivity, specificity, positive predictive value and negative predictive value were 53.8, 45.7, 35.4, 64.2 % for TAG, 82.7, 74.5, 64.2, 88.6 % for FFR , 84.6, 39.4, 43.6, 82.2 % for CCTA stenosis, respectively. The AUC by ROC curve analysis for FFR (0.79) demonstrated greater discrimination of hemodynamic ischemia compared to TAG (0.50, p < 0.0001 vs. FFR ), CCTA stenosis (0.62, p = 0.0004 vs. FFR ) and the combination of the two (0.63, p = 0.004 vs. FFR ). These results remained consistent regardless of the number of CCTA slices. FFR allows identification of lesion-specific ischemia using invasive FFR as a reference standard with greater diagnostic accuracy than TAG, CCTA stenosis, or the combination of the two. CT CT CT CT CT CT CT C

Reproducibility of computed tomography angiography data analysis using semiautomated plaque quantification software: implications for the design of longitudinal studies.

Reproducibility of the quantitative assessment of atherosclerosis by computed tomography coronary angiography (CTCA) is paramount for the design of longitudinal studies. The purpose of this study was to assess the inter- and intra-observer reproducibility using semiautomated CT plaque analysis software in symptomatic individuals. CTCA was performed in 10 symptomatic patients after percutaneous treatment of the culprit lesions and was repeated after 3 years. The plaque quantitative analysis was performed in untreated vessels with mild-to-moderate atherosclerosis and included geometrical and compositional characteristics using semiautomated CT plaque analysis software. A total of 945 matched cross-sections from 21 segments were analyzed independently by a second reviewer to assess inter-observer variability; the first observer repeated all the analyses after 3 months to assess intra-observer variability. The observer variability was also compared to the absolute plaque changes detected over time. Agreement was evaluated by Bland-Altman analysis and concordance correlation coefficient. Inter-observer relative differences for lumen, vessel, plaque area and plaque burden were 1.2, 0.6, 2.2, 1.6% respectively. Intra-observer relative differences for lumen, vessel, plaque area and plaque burden were 1.0, 0.4, 0.2, 0.4% respectively. For the average plaque attenuation values the inter- and intra-observer variability was 5 and 2% respectively. For the % low-attenuation-plaque the inter- and intra-observer variability was 16 and 6% respectively. The absolute intra-observer variability for the plaque burden was 1.30 \ub1 1.09%, while the temporal plaque burden difference was 3.55 \ub1 3.02 % (p = 0.001). The present study shows that the geometrical assessment of coronary atherosclerosis by CTCA is highly reproducible within and between observers using semiautomated quantification software and that serial plaque changes can be detected beyond observer variability. The compositional measurements are more variable between observers than geometrical measurements

Natural history of coronary atherosclerosis by multislice computed tomography.

OBJECTIVES: This study sought to analyze the natural history of coronary atherosclerosis by multislice computed tomography (MSCT) and assess the serial changes in coronary plaque burden, lumen dimensions, and arterial remodeling. BACKGROUND: MSCT can comprehensively assess coronary atherosclerosis by combining lumen and plaque size parameters. METHODS: Thirty-two patients with acute coronary syndromes underwent 64-slice computed tomography angiography after percutaneous coronary intervention at baseline and after a median of 39 months. All patients received contemporary medical treatment. All available coronary segments in every subject were analyzed. The progression of atherosclerosis per segment and per patient was assessed by means of change in percent atheroma volume (PAV), change in normalized total atheroma volume (TAVnorm), and percent change in TAV (% change in TAV). Serial coronary remodeling was also assessed. Measures of lumen stenosis included percent diameter stenosis (%DS), minimum lumen diameter (MLD), percent area stenosis (%AS), and minimum lumen area (MLA). For each patient, the mean of all matched segments was calculated at the 2 time points. Clinical events at follow-up were documented. RESULTS: The PAV did not change significantly (-0.15 \ub1 3.64%, p = 0.72). The mean change in TAVnorm was 47.36 \ub1 143.24 mm(3) (p = 0.071), and the % change in TAV was 6.7% (p = 0.029). The MLD and MLA increased by 0.15 mm (-0.09 to 0.24, p = 0.039) and 0.52 mm(2) (-0.38 to 1.04, p = 0.034) respectively, which was accompanied by vessel enlargement, with 53% of the patients showing expansive positive remodeling. Patients with clinical events had a larger TAVnorm at baseline (969.72 mm(3) vs. 810.77 mm(3), p = 0.010). CONCLUSIONS: MSCT can assess the progression of coronary atherosclerosis and may be used for noninvasive monitoring of pharmacological interventions in coronary artery disease

Natural History of Coronary Atherosclerosis by Multislice Computed Tomography

OBJECTIVES This study sought to analyze the natural history of coronary atherosclerosis by multislice computed tomography (MSCT) and assess the serial changes in coronary plaque burden, lumen dimensions, and arterial remodeling. BACKGROUND MSCT can comprehensively assess coronary atherosclerosis by combining lumen and plaque size parameters. METHODS Thirty-two patients with acute coronary syndromes underwent 64-slice computed tomography angiography after percutaneous coronary intervention at baseline and after a median of 39 months. All patients received contemporary medical treatment. All available coronary segments in every subject were analyzed. The progression of atherosclerosis per segment and per patient was assessed by means of change in percent atheroma volume (PAV), change in normalized total atheroma volume (TAVnorm), and RESULTS The PAV did not change significantly (-0.15 +/- 3.64%, p = 0.72). The mean change in TAVnorm was 47.36 +/- 143.24 mm(3) (p = 0.071), and the % change in TAV was 6.7% (p = 0.029). The MLD and MLA increased by 0.15 mm (-0.09 to 0.24, p = 0.039) and 0.52 mm(2) (-0.38 to 1.04, p = 0.034) respectively, which was accompanied by vessel enlargement, with 53% of the patients showing expansive positive remodeling. Patients with clinical events had a larger TAVnorm at baseline (969.72 mm(3) vs. 810 CONCLUSIONS MSCT can assess the progression of coronary atherosclerosis and may be used for noninvasive monitoring of pharmacological interventions in coronary artery disease. (PROSPECT: An Imaging Study in Patients With Unstable Atherosclerotic Lesions; NCT00180466) (J Am Coll Cardiol Img 2012;5:528-37) 0 2012 by the American College of Cardiology Foundatio

Quantitative Computed Tomographic Coronary Angiography Does It Predict Functionally Significant Coronary Stenoses?

Cardiovascular Aspects of Radiolog

Standardized evaluation framework for evaluating coronary artery stenosis detection, stenosis quantification and lumen segmentation algorithms in computed tomography angiography

Though conventional coronary angiography (CCA) has been the standard of reference for diagnosing coronary artery disease in the past decades, computed tomography angiography (CIA) has rapidly emerged, and is nowadays widely used in clinical practice. Here, we introduce a standardized evaluation framework to reliably evaluate and compare the performance of the algorithms devised to detect and quantify the coronary artery stenoses, and to segment the coronary artery lumen in CIA data. The objective of this evaluation framework is to demonstrate the feasibility of dedicated algorithms to: (I) (semi-)automatically detect and quantify stenosis on CIA, in comparison with quantitative coronary angiography (QCA) and CIA consensus reading, and (2) (semi-)automatically segment the coronary lumen on CIA, in comparison with expert's manual annotation. A database consisting of 48 multicenter multivendor cardiac CIA datasets with corresponding reference standards are described and made available. The algorithms from 11 research groups were quantitatively evaluated and compared. The results show that (1) some of the current stenosis detection/quantification algorithms may be used for triage or as a second-reader in clinical practice, and that (2) automatic lumen segmentation is possible with a precision similar to that obtained by experts. The framework is open for new submissions through the website, at http://coronary.bigr.nl/stenoses/. (C) 2013 Elsevier B.V. All rights reserved