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Chatzizisis, Yiannis

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Chatzizisis

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Yiannis

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Chatzizisis, Yiannis
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    Contrast inhomogeneity in CT angiography of the abdominal aortic aneurysm
    (Elsevier BV, 2016) George, Elizabeth; Giannopoulos, Andreas A.; Aghayev, Ayaz; Rohatgi, Saurabh; Imanzadeh, Amir; Antoniadis, Antonios P.; Kumamaru, Kanako; Chatzizisis, Yiannis; Dunne, Ruth Mary; Steigner, Michael; Hanley, Michael; Gravereaux, Edwin; Rybicki, Frank John; Mitsouras, Dimitrios
    Background If undetected, infrarenal Abdominal Aortic Aneurysm (AAA) growth can lead to rupture, a high-mortality complication. Some AAA patients exhibit inhomogeneous luminal contrast attenuation at first-pass CT angiography (CTA). This study assesses the association between this observation and aneurysm growth. Methods Sixty-seven consecutive pre-repair AAA CTAs were included in this retrospective study. The “Gravitational Gradient” (GG), defined as the ratio of the mean attenuation in a region-of-interest placed posteriorly to that in a region-of-interest placed anteriorly within the lumen of the aortic aneurysm on a single axial slice, and the maximum aneurysm diameter were measured from each CT data set. “AAA Contrast Inhomogeneity” was defined as the absolute value of the difference between the GG and 1.0. Univariate and multivariate logistic regression was used to assess the association of aneurysm growth >0.4 and >1.0 cm/year to AAA Contrast Inhomogeneity, aneurysm diameter, patient characteristics and cardiovascular co-morbidities. Results AAA Contrast Inhomogeneity was not correlated to aneurysm diameter (p=0.325). In multivariable analysis that included initial aneurysm diameter and AAA Contrast Inhomogeneity, both factors were significantly associated with rapid aneurysm growth (initial diameter: p=0.0029 and 0.011, and, AAA Contrast Inhomogeneity: p=0.045 and 0.048 for growth >0.4 cm/year and >1 cm/year respectively). Conclusions AAA Contrast Inhomogeneity is a common observation in first-pass CTA. It is associated with rapid aneurysm growth, independent of and incremental to aneurysm diameter.
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    Accuracy and reproducibility of automated, standardized coronary transluminal attenuation gradient measurements
    (Springer Nature, 2014) Chatzizisis, Yiannis; George, Elizabeth; Cai, Tianrun; Fulwadhva, Urvi P; Kumamaru, Kanako; Schultz, Kurt; Fujisawa, Yasuko; Rassi, Carlos; Steigner, Michael; Mather, Richard T.; Blankstein, Ron; Rybicki, Frank John; Mitsouras, Dimitrios
    Purpose Coronary Computed Tomography Angiography (CCTA) contrast opacification gradients, or Transluminal Attenuation Gradients (TAG) offer incremental value to predict functionally significant lesions. This study introduces and evaluates an automated gradients software package that can potentially supplant current, labor-intensive manual TAG calculation methods. Methods All 60 major coronary arteries in 20 patients who underwent a clinically indicated single heart beat 320×0.5 mm detector row CCTA were retrospectively evaluated by two readers using a previously validated manual measurement approach and two additional readers who used the new automated gradient software. Accuracy of the automated method against the manual measurements, considered the reference standard, was assessed via linear regression and Bland-Altman analyses. Inter- and intra-observer reproducibility and factors that can affect accuracy or reproducibility of both manual and automated TAG measurements, including CAD severity and iterative reconstruction, were also assessed. Results Analysis time was reduced by 68% when compared to manual TAG measurement. There was excellent correlation between automated TAG and the reference standard manual TAG. Bland-Altman analyses indicated low mean differences (1 HU/cm) and narrower inter- and intra-observer limits of agreement for automated compared to manual measurements (25% and 36% reduction with automated software, respectively). Among patient and technical factors assessed, none affected agreement of manual and automated TAG measurement. Conclusion Automated 320×0.5 mm detector row gradient software reduces computation time by 68% with high accuracy and reproducibility.
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    Tumor Encasement of the Right Coronary Artery: Role of Anatomic and Functional Imaging in Diagnosis and Therapeutic Management
    (Bentham Open, 2014) Juan, Yu-Hsiang; Chatzizisis, Yiannis; Saboo, Sachin S; Rocha, Tatiana; Steigner, Michael
    We presented two rare cases of mediastinal tumor encasing the right coronary artery (RCA), one with recurrent metastatic thymoma and another with primary poorly differentiated neoplasm. Different degrees and locations of RCA involvement were noted. The treatment approach varied from conservative to surgical. Coronary artery involvement by mediastinal tumors is important to be investigated with imaging as it may guide the surgical planning.
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    Flow Perturbation Mediates Neutrophil Recruitment and Potentiates Endothelial Injury via TLR2 in MiceNovelty and Significance
    (Ovid Technologies (Wolters Kluwer Health), 2017) Franck, Grégory; Mawson, Thomas; Sausen, Grasiele; Salinas, Manuel; Masson, Gustavo Santos; Cole, Andrew; Beltrami-Moreira, Marina; Chatzizisis, Yiannis; Quillard, Thibault; Tesmenitsky, Yevgenia; Shvartz, Eugenia; Sukhova, Galina; Swirski, Filip; Nahrendorf, Matthias; Aikawa, Elena; Croce, Kevin; Libby, Peter