Aim. The aim of my doctoral thesis was to estimate the accuracy of coronary computed tomography angiography (CTA) in quantifying calcified and non-calcified coronary artery atherosclerotic plaques in comparison with intravascular ultrasound (IVUS). Moreover, the ability of coronary CTA in predicting the IVUS-derived plaque tissue characterization ("virtual histology", IVUS-VH) was assessed. Background. Coronary CTA proved to be reliable in detecting and quantifying non-calcified coronary plaques. However, calcified plaques are still challenging its diagnostic accuracy, due to the partial volume averaging effect, leading to overrepresentation of high attenuation objects. Intravascular ultrasound-VH uses spectral analysis of IVUS radiofrequency data to construct tissue maps that classify plaques into four major components: a) fibrous, b) fibro-fatty, c) necrotic core, and d) calcium. It is one of the most promising tools developed for in vivo plaque tissue characterization and correlates well with histology. Computed tomography plaque characterization demonstrated to be a feasible but challenging task. Currently, there are no published studies comparing coronary CTA plaque analysis with IVUS-VH. Methods. Forty-four patients with stable angina pectoris who underwent 64-multi-detector CTA, invasive coronary angiography, and IVUS have been enrolled. The coronary tree segments under investigation at coronary CTA after comparison with invasive angiography and IVUS, based on landmark branches detected with all these three techniques have been selected. Coronary CTA images with a dedicated workstation in multiplanar reformatted reconstructions on a plane perpendicular to the vessel longitudinal axis were analyzed, blinded to invasive angiography and IVUS results. For comparison with IVUS, the plaque area, as well as the lumen and vessel cross sectional area (CSA) at 3 mm intervals in the segments under investigation were investigated. Atherosclerotic plaques were characterized based on CT attenuation values (HU) and their components classified as necrotic core (HU 0-29), fibro-fatty (HU 30-79), fibrous (HU 80-129), and calcified (HU ? 130). . Results. Coronary CTA was considered of diagnostic quality in 39 patients, 42 vessels. Intravascular ultrasound-determined mean vessel CSA, mean lumen CSA, mean atherosclerotic plaque area and burden were predicted by coronary CTA: R2 0.6 (p <0.0001), 0.5 (p <0.0001), 0.3 (p <0.0001), and 0.2 (p = 0.04), respectively. After selecting the sections with a calcified plaque component, coronary CTA was still able to predict IVUS-derived vessel CSA, mean lumen CSA, mean atherosclerotic plaque area and burden: R2 0.5 (p <0.0001), 0.6 (p <0.0001), 0.2 (p = 0.02), and 0.2 (p = 0.04), respectively. Finally, coronary CTA plaque tissue characterization was able to predict IVUS-VH-derived atherosclerotic plaque components: R2 0.8 for necrotic core (p = 0.02), 0.5 for fibro-fatty (p = 0.04), 0.5 for fibrous (p = 0.04), 0.7 for calcified (p = 0.02). Conclusions. Coronary CTA is a robust tool in measuring vessel and lumen CSA in presence of calcified and non-calcified atherosclerotic coronary plaques. "Virtual histology" is feasible with coronary CTA and its plaque characterization predicts IVUS-VH results.

Comparative study at computed tomography angiography and intravascular ultrasound of coronary atherosclerotic plaques / Maiolino, Giuseppe. - (2008).

Comparative study at computed tomography angiography and intravascular ultrasound of coronary atherosclerotic plaques

Maiolino, Giuseppe
2008

Abstract

Aim. The aim of my doctoral thesis was to estimate the accuracy of coronary computed tomography angiography (CTA) in quantifying calcified and non-calcified coronary artery atherosclerotic plaques in comparison with intravascular ultrasound (IVUS). Moreover, the ability of coronary CTA in predicting the IVUS-derived plaque tissue characterization ("virtual histology", IVUS-VH) was assessed. Background. Coronary CTA proved to be reliable in detecting and quantifying non-calcified coronary plaques. However, calcified plaques are still challenging its diagnostic accuracy, due to the partial volume averaging effect, leading to overrepresentation of high attenuation objects. Intravascular ultrasound-VH uses spectral analysis of IVUS radiofrequency data to construct tissue maps that classify plaques into four major components: a) fibrous, b) fibro-fatty, c) necrotic core, and d) calcium. It is one of the most promising tools developed for in vivo plaque tissue characterization and correlates well with histology. Computed tomography plaque characterization demonstrated to be a feasible but challenging task. Currently, there are no published studies comparing coronary CTA plaque analysis with IVUS-VH. Methods. Forty-four patients with stable angina pectoris who underwent 64-multi-detector CTA, invasive coronary angiography, and IVUS have been enrolled. The coronary tree segments under investigation at coronary CTA after comparison with invasive angiography and IVUS, based on landmark branches detected with all these three techniques have been selected. Coronary CTA images with a dedicated workstation in multiplanar reformatted reconstructions on a plane perpendicular to the vessel longitudinal axis were analyzed, blinded to invasive angiography and IVUS results. For comparison with IVUS, the plaque area, as well as the lumen and vessel cross sectional area (CSA) at 3 mm intervals in the segments under investigation were investigated. Atherosclerotic plaques were characterized based on CT attenuation values (HU) and their components classified as necrotic core (HU 0-29), fibro-fatty (HU 30-79), fibrous (HU 80-129), and calcified (HU ? 130). . Results. Coronary CTA was considered of diagnostic quality in 39 patients, 42 vessels. Intravascular ultrasound-determined mean vessel CSA, mean lumen CSA, mean atherosclerotic plaque area and burden were predicted by coronary CTA: R2 0.6 (p <0.0001), 0.5 (p <0.0001), 0.3 (p <0.0001), and 0.2 (p = 0.04), respectively. After selecting the sections with a calcified plaque component, coronary CTA was still able to predict IVUS-derived vessel CSA, mean lumen CSA, mean atherosclerotic plaque area and burden: R2 0.5 (p <0.0001), 0.6 (p <0.0001), 0.2 (p = 0.02), and 0.2 (p = 0.04), respectively. Finally, coronary CTA plaque tissue characterization was able to predict IVUS-VH-derived atherosclerotic plaque components: R2 0.8 for necrotic core (p = 0.02), 0.5 for fibro-fatty (p = 0.04), 0.5 for fibrous (p = 0.04), 0.7 for calcified (p = 0.02). Conclusions. Coronary CTA is a robust tool in measuring vessel and lumen CSA in presence of calcified and non-calcified atherosclerotic coronary plaques. "Virtual histology" is feasible with coronary CTA and its plaque characterization predicts IVUS-VH results.
2008
coronary computed tomography, intravascular ultrasound
Comparative study at computed tomography angiography and intravascular ultrasound of coronary atherosclerotic plaques / Maiolino, Giuseppe. - (2008).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3425553
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