1,720,996 research outputs found
Association between aortic supravalvular stenosis and coronary ectasia
Full text linkFil: De Zan, Macarena C. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Carrascosa, Patricia. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Deviggiano, Alejandro. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Basara, Monica. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Diagnostico Maipu, Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin
Dual energy cardiac computed tomography
No full textConventional single energy CT suffers from technical limitations related to the polychromatic nature of X-rays. Dual energy cardiac CT (DE CT) shows promise to attenuate and even overcome some of these limitations, and might broaden the scope of patients eligible for cardiac CT towards the inclusion of higher risk patients. This might be achieved as a result of both safety (contrast reduction) and physiopathological (myocardial perfusion and characterization) issues. In this article, we will review the main clinical cardiac applications of DE CT, that can be summarized in two core aspects: coronary artery evaluation, and myocardial evaluation.Fil: Carrascosa, Patricia. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Deviggiano, Alejandro. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Diagnostico Maipu, Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Myocardial signal density levels and beam-hardening artifact attenuation using dual-energy computed tomography
Full text linkThe assessment of myocardial perfusion using single-energy (SE) imaging is influenced by beam-hardening artifacts (BHA). We sought to explore the ability of dual-energy (DE) imaging to attenuate the presence of BHA. Myocardial signal density (SD) was evaluated in 2240 myocardial segments (112 for each energy level) and in 320 American Heart Association segments among the SE group. Compared to DE reconstructions at the best energy level, SE acquisitions showed no significant differences overall regarding myocardial SD or signal-to-noise ratio. The segments most commonly affected by BHA showed significantly lower myocardial SD at the lowest energy levels, progressively normalizing at higher energy levels.Fil: Rodriguez Granillo, Gaston Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentina. Diagnóstico Maipú; ArgentinaFil: Carrascosa, Patricia. Diagnóstico Maipú; ArgentinaFil: Cipriano, Silvina. Diagnóstico Maipú; ArgentinaFil: de Zan, Macarena. Diagnóstico Maipú; ArgentinaFil: Deviggiano, Alejandro. Diagnóstico Maipú; ArgentinaFil: Capunay, Carlos. Diagnóstico Maipú; ArgentinaFil: Cury, Ricardo C.. Miami Cardiac and Vascular Institute; Estados Unidos. Baptist Health of South Florida; Estados Unido
Start-up digital: Goldie Health ID
No full textFil: Rullán Corna, Nicolás Félix. Universidad de San Andrés. Escuela de Negocios; Argentina
Dual energy imaging and intracycle motion correction for CT coronary angiography in patients with intermediate to high likelihood of coronary artery disease
Full text linkWe explored whether intracycle motion correction algorithms (MCAs) might be applicable to dual energy computed tomography coronary angiography in patients with intermediate to high likelihood of coronary artery disease. MCA reconstructions were associated with higher interpretability rates (96.7% vs 87.9%, P < .001), image quality scores (4.12±0.9 vs. 3.76±1.0; P < .0001), and diagnostic performance [area under the curve of 0.95 (95% confidence interval [CI] 0.92-0.97) vs 0.89 (95% CI 0.86-0.92); P < .0001] compared to conventional reconstructions. In conclusion, application of intracycle MCA reconstructions to dual energy computed tomography acquisitions was feasible and resulted in significantly higher image quality scores, interpretability, and diagnostic performance.Fil: Carrascosa, Patricia. Diagnóstico Maipú; ArgentinaFil: Deviggiano, Alejandro. Diagnóstico Maipú; ArgentinaFil: Leipsic, Jonathon A.. St. Paul's Hospital; CanadáFil: Capunay, Carlos. Diagnóstico Maipú; ArgentinaFil: De Zan, Macarena C.. Diagnóstico Maipú; ArgentinaFil: Goldsmit, Alejandro. Sanatorio Güemes; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Diagnóstico Maipú; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin
Regional differences of fat depot attenuation using non-contrast, contrast-enhanced, and delayed-enhanced cardiac CT
No full textBackground: Regional fat density assessed by computed tomography (CT) has been suggested as a marker of perivascular adipose tissue inflammation. Dual energy CT (DECT) allows improved tissue characterization compared to conventional CT. Purpose: To explore whether DECT might aid regional fat density discrimination. Material and Methods: We included patients who had completed a non-enhanced cardiac CT scan, CT coronary angiography (CTCA), and a delayed enhancement CT. Attenuation levels (Hounsfield units [HU]) were assessed at the epicardial, paracardial, visceral, and subcutaneous fat. The number of coronary segments with disease (SIS) was calculated. Results: A total of 36 patients were included in the analysis. Twenty-six (72%) patients had evidence of obstructive disease at CCTA and 25 (69%) patients had evidence of previous myocardial infarction. At non-contrast CT, we did not identify significant attenuation differences between epicardial, paracardial, subcutaneous, and visceral fat depots (−110.8 ± 9 HU, vs. −113.7 ± 9 HU, vs. −114.7 ± 8 HU, vs. −113.8 ± 11 HU, P = 0.36). Significant attenuation differences were detected between fat depots at mid and low energy levels, both at CTCA and delayed-enhancement scans (P < 0.05 for all). Epicardial fat showed the least negative attenuation, irrespective of the acquisition mode; epicardial fat evaluated at 40 keV was related to the SIS (r = 0.37, P = 0.03). Conclusions: In this study, regional fat depots amenable to examination during thoracic CT scans have distinctive regional attenuation values. Furthermore, such differences were better displayed using contrast-enhanced monochromatic imaging at low energy levels.Fil: Rodriguez Granillo, Gaston Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Capunay, Carlos. No especifíca;Fil: Deviggiano, Alejandro. No especifíca;Fil: De Zan, Macarena. No especifíca;Fil: Carrascosa, Patricia. No especifíca
Effect of Intracycle Motion Correction Algorithm on Image Quality and Diagnostic Performance of Computed Tomography Coronary Angiography in Patients with Suspected Coronary Artery Disease
Full text linkRationale and objectives: We sought to explore the impact of intracycle motion correction algorithms (MCA) in the interpretability and diagnostic accuracy of computed tomography coronary angiography (CTCA) performed in patients suspected of coronary artery disease (CAD) referred to invasive coronary angiography. Materials and Methods: Patients with suspected CAD referred to invasive coronary angiography previously underwent CTCA. Patients under rate-control medications were advised to withhold for the previous 24hours. The primary end point of the study was to evaluate image interpretability and diagnostic performance of MCA compared to conventional reconstructions in patients referred to invasive angiography because of suspected CAD. Results: Thirty-five patients were prospectively included in the study protocol. The mean age was 61.4±9.4years. Twenty-seven (77%) patients were men. A total of 533 coronary segments were evaluated using conventional and MCA reconstructions. MCA reconstructions were associated to higher interpretability rates (525 of 533, 98.5% vs. 515 of 533, 96.6 %; P<.001) and image quality scores (3.88±0.54 vs. 3.78±0.76; P<.0001) compared to conventional reconstructions. Although only mild, a significant difference was observed regarding the diagnostic performance between reconstruction modes, with an area under the curve of 0.90 (0.87-0.92) versus 0.89 (0.86-0.92), respectively, for MCA and conventional reconstructions (. P=.0447). Conclusions: In this pilot investigation, MCA reconstructions performed in patients with suspected CAD were associated to higher interpretability rates and image quality scores compared to conventional reconstructions, although only mild differences were observed regarding the diagnostic performance between reconstruction modes.Fil: Carrascosa, Patricia. Sanatorio Güemes; Argentina. Diagnóstico Maipú; ArgentinaFil: Deviggiano, Alejandro. Sanatorio Güemes; Argentina. Diagnóstico Maipú; ArgentinaFil: Capunay, Carlos. Sanatorio Güemes; Argentina. Diagnóstico Maipú; ArgentinaFil: De Zan, Macarena C.. Sanatorio Güemes; Argentina. Diagnóstico Maipú; ArgentinaFil: Goldsmit, Alejandro. Sanatorio Güemes; Argentina. Diagnóstico Maipú; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Diagnóstico Maipú; Argentina. Sanatorio Güemes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Substantial iodine volume load reduction in CT angiography with dual-energy imaging: insights from a pilot randomized study
Full text linkWe explored whether dual-energy computed tomography (DECT) can allow a significant reduction in iodinated contrast volume during computed tomography angiography (CTA) without hampering image quality or assessibility. We prospectively randomized patients clinically referred to CTA to single energy computed tomography (SECT) with full iodine volume load (group A), DECT with 50 % iodine volume load (group B), DECT with 40 % iodine volume load (group C), and DECT with 30 % iodine volume load (group D); and compared image quality and assessibility. Eighty patients were enrolled and prospectively randomized. The mean age was 61.7 ± 15.0 years and 56 (71 %) patients were male. The demographical characteristics, body mass index, or mean radiation dose did not differ between groups. Significant reductions in total contrast volume were achieved in groups B, C, and D; with mean administrated contrast volumes of 90.3 ± 10.1, 39.5 ± 4.6, 28.3 ± 6.5, and 23.9 ± 6.0 mL, respectively, in groups A to D (p < 0.0001). With regard to image quality, no significant decrease in the Likert scale was observed with reductions of up to 60 % of the contrast volume (groups B and C). DECT at 50–60 keV in association with up to 60 % iodine load reduction, allowed similar signal density, image noise, and signal to noise ratio that SECT imaging with full iodine load. In this pilot, prospective, randomized study, dual energy CTA with up to 60 % iodine volume load reduction provided similar image quality and assessibility than full iodine load with conventional SECT imaging.Fil: Carrascosa, Patricia. Diagnostico Maipu; ArgentinaFil: Capunay, Carlos. Diagnostico Maipu; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Diagnostico Maipu; ArgentinaFil: Deviggiano, Alejandro. Diagnostico Maipu; ArgentinaFil: Vallejos, Javier. Diagnostico Maipu; ArgentinaFil: Leipsic, Jonathon A.. St. Paul’s Hospital; Canad
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