Beam hardening artifact reduction using dual energy computed tomography: implications for myocardial perfusion studies

Background: Myocardial perfusion computed tomography (CTP) using conventional single energy (SE) imaging is influenced by the presence of beam hardening artifacts (BHA), occasionally resembling perfusion defects and commonly observed at the left ventricular posterobasal wall (PB). We therefore sought to explore the ability of dual energy (DE) CTP to attenuate the presence of BHA. Methods: Consecutive patients without history of coronary artery disease who were referred for computed tomography coronary angiography due to atypical chest pain and a normal stress-rest SPECT and had absence or mild coronary atherosclerosis constituted the study population. The study group was acquired using DE and the control group using SE imaging. Results: Demographical characteristics were similar between groups, as well as the heart rate and the effective radiation dose. Myocardial signal density (SD) levels were evaluated in 280 basal segments among the DE group (140 PB segments for each energy level from 40 keV to 100 keV; and 140 reference segments), and in 40 basal segments (at the same locations) among the SE group. Among the DE group, myocardial SD levels and myocardial SD ratio evaluated at the reference segment were higher at low energy levels, with significantly lower SD levels at increasing energy levels. Myocardial signal-to-noise ratio was not significantly influenced by the energy level applied, although 70 keV was identified as the energy level with the best overall signal-to-noise ratio. Significant differences were identified between the PB segment and the reference segment among the lower energy levels, whereas at ≥ 70 keV myocardial SD levels were similar. Compared to DE reconstructions at the best energy level (70 keV), SE acquisitions showed no significant differences overall regarding myocardial SD levels among the reference segments. Conclusions: Beam hardening artifacts that influence the assessment of myocardial perfusion can be attenuated using DE at 70 keV or higher.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, Silvia. 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 and Baptist Health; Estados Unido

Myocardial signal density levels and beam-hardening artifact attenuation using dual-energy computed tomography

The 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

Dual energy imaging and intracycle motion correction for CT coronary angiography in patients with intermediate to high likelihood of coronary artery disease

We 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

Reproducibility of Gadolinium Enhancement Patterns and Wall Thickness in Hypertrophic Cardiomyopathy

Abstract Background: Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is limited. Objective: To explore the reproducibility of regional wall thickness (WT), LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR). Methods: The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE); and the pattern of LGE-CMR was defined for each segment. Results: A total of 42 patients (672 segments) with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%), with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC) of 0.95 (95% CI 0.93-0.96). Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%), with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98). The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%), with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97). The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%), with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99). Conclusions: The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE

Association between aortic supravalvular stenosis and coronary ectasia

Fil: 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

Wall Thickness and Patterns of Fibrosis in Hypertrophic Cardiomyopathy Assessed by Cardiac Magnetic Resonance Imaging

Background: Hypertrophic cardiomyopathy is the most common genetic cardiac disease and the main cause of sudden death in theyoung. Cardiac magnetic resonance imaging can characterize the different forms of hypertrophic cardiomyopathy and detect myocardialfibrosis by late gadolinium enhancement.Objectives: The aim of this study was to characterize the regional distribution of left ventricular wall thickness and its relationwith myocardial fibrosis, and also quantify the percentage and determine the different patterns of left gadolinium enhancement inpatients with hypertrophic cardiomyopathy evaluated with cardiac magnetic resonance imaging.Methods: This observational study evaluated patients with hypertrophic cardiomyopathy undergoing contrast-enhanced cardiacmagnetic resonance imaging. The results were compared with a group of control patients. Hypertrophic cardiomyopathy morphologywas evaluated and the percentage of late gadolinium enhancement was determined.Results: Maximum wall thickness was observed in the mid inferoseptal (16.8±5.3 mm), basal anteroseptal (16.5±6.2 mm), and midanteroseptal segments (15.4±6.2 mm). Thirty patients (71%) with hypertrophic cardiomyopathy presented late gadolinium enhancementin 141/672 (21%) of the segments evaluated. Late gadolinium enhancement was predominantly intramyocardial (n=103,73%). A significant association was found between the percentage of late gadolinium enhancement in the left ventricle and maximummyocardial wall thickness.Conclusions: Maximum wall thickness was more frequently observed in the basal and mid septal segments. Two-thirds of thesepatients presented late gadolinium enhancement which was associated with maximum wall thicknessIntroducción: La miocardiopatía hipertrófica (MCH) es la enfermedad cardiovascular hereditaria más frecuente  y la principal causa de muerte súbita en los individuos jóvenes. La resonancia magnética cardíaca (RMC) permite  caracterizar  las distintas formas de MCH  y detectar  fibrosis miocárdica a través del realce tardío (RT). Objetivos: Caracterizar la distribución regional de los espesores miocárdicos y su relación con la  fibrosis miocárdica así como cuantificar el porcentaje  y determinar los diferentes patrones de RT en paciente con MCH evaluados por RMC. Materiales y métodos: El presente fue un estudio observacional que evaluó  pacientes con diagnóstico de MCH  a través de la RMC con contraste endovenoso. Los resultados se compararon con un grupo de pacientes control. Se efectuó la evaluación morfológica y se determinó  el porcentaje total de RT (% RT). Resultados: El espesor máximo de los pacientes con MCH se evidenció en el segmento inferoseptal medio 16.8±5.3 mm, seguido por los segmentos anteroseptal basal 16.5±6.2 mm y anteroseptal medial 15.4±6.2 mm. Presentaron RT 30 (71 %) pacientes con MCH y 141/672 (21 %) de los segmentos evaluados. La distribución del RT fue predominantemente intramiocárdica (n=103, 73%). Se encontró una relación significativa entre % RT del ventrículo izquierdo y el espesor miocárdico máximo. Conclusión: La localización más frecuente del espesor parietal máximo se encontró a nivel septal basal y medial. En dos tercios de estos pacientes se detectó RT, el cual se asoció al espesor miocárdico máximo

Effect of Intracycle Motion Correction Algorithm on Image Quality and Diagnostic Performance of Computed Tomography Coronary Angiography in Patients with Suspected Coronary Artery Disease

Rationale 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

Extensión y distribución espacial de la carga ateroesclerótica mediante imágenes monocromáticas virtuales derivadas de tomografía computarizada de doble energía

Introduction and objectives We explored the differences between atherosclerotic burden with invasive coronary angiography and virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography. Methods Eighty consecutive patients referred for invasive coronary angiography underwent dual-energy computed tomography coronary angiography and were categorized according to the atherosclerotic burden extent using the modified Duke prognostic coronary artery disease index, coronary artery disease extension score, segment involvement score, and the segment stenosis score. Results The mean segment involvement score (8.2 ± 3.9 vs 6.0 ± 3.7; P < .0001), modified Duke index (4.33 ± 1.6 vs 4.0 ± 1.7; P = .003), coronary artery disease extension score (4.84 ± 1.8 vs 4.43 ± 2.1; P = .005), and the median segment stenosis score (13.5 [9.0-18.0] vs 9.5 [5.0-15.0]; P < .0001) were significantly higher on dual-energy computed tomography compared with invasive angiography. Dual-energy computed tomography showed a significantly higher number of patients with any left main coronary artery lesion (46 [58%] vs 18 [23%]; P < .0001) and with severe proximal lesions (0.28 ± 0.03 vs 0.26 ± 0.03; P < .0001) than invasive angiography. Levels of coronary artery calcification below and above the median showed a sensitivity, specificity, positive predictive value, and negative predictive value of 100% and 97%; 86% and 50%; 93% and 95%; 100% and 67% for the identification of ≥ 50% stenosis. Conclusions Dual-energy computed tomography coronary angiography identified a significantly larger atherosclerotic burden compared with invasive coronary angiography, particularly involving the proximal segments.Introducción y objetivos Se analizaron las diferencias de carga ateroesclerótica observadas entre la coronariografía invasiva y las imágenes monocromáticas virtuales obtenidas con la tomografía computarizada de doble energía. Métodos Se examinó con tomografía computarizada de doble energía y se clasificó a 80 pacientes consecutivos remitidos a una coronariografía invasiva según el grado de carga ateroesclerótica utilizando el índice pronóstico de enfermedad coronaria de Duke modificado, la puntuación de extensión de la enfermedad coronaria, la puntuación de afección de segmentos y la puntuación de estenosis de segmentos. Resultados La media de la puntuación de afección de segmento (8,2 ± 3,9 frente a 6,0 ± 3,7; p < 0,0001), el índice de Duke modificado (4,33 ± 1,6 frente a 4,0 ± 1,7; p = 0,003), la puntuación de extensión de la enfermedad coronaria (4,84 ± 1,8 frente a 4,43 ± 2,1; p = 0,005) y la mediana de la puntuación de estenosis de segmento (13,5 [9,0-18,0] frente a 9,5 [5,0-15,0]; p < 0,0001) fueron significativamente superiores con la tomografía computarizada de doble energía que con la coronariografía invasiva. La tomografía computarizada de doble energía mostró un número de pacientes con alguna lesión del tronco coronario izquierdo significativamente mayor (46 [58%] frente a 18 [23%]; p < 0,0001) y con lesiones proximales graves (0,28 ± 0,03 frente a 0,26 ± 0,03; p < 0,0001) en comparación con lo observado en la coronariografía invasiva. Los grados de calcificación arterial coronaria por debajo y por encima de la mediana mostraron sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo del 100 y el 97%; el 86 y el 50%; el 93 y el 95% y el 100 y el 67% para la identificación de estenosis ≥ 50%. Conclusiones La angiografía coronaria con tomografía computarizada de energía dual identificó una carga ateroesclerótica significativamente mayor que la observada con la coronariografía invasiva, en especial por lo que respecta a la afección de los segmentos proximales.Fil: Rodriguez Granillo, Gaston Alfredo. Diagnostico 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; ArgentinaFil: Carrascosa, Patricia. Diagnostico Maipú; ArgentinaFil: Deviggiano, Alejandro. Diagnostico Maipú; ArgentinaFil: Capunay, Carlos. Diagnostico Maipú; ArgentinaFil: De Zan, Macarena C.. Diagnostico Maipú; ArgentinaFil: Goldsmit, Alejandro. Sanatorio Güemes; Argentin

Relationship between left atrial dimensions and global and regional fat depots

Antecedentes y objetivos: La relación entre los depósitos de grasa corporal y las dimensiones de la aurícula izquierda (AI) no ha sido del todo explorada. Nuestro objetivo es determinar si existe relación no solo con los depósitos de grasa corporal totales, sino específicamente con los depósitos grasos regionales. Materiales y métodos: Estudio observacional, retrospectivo, que incluyó pacientes consecutivos remitidos a nuestra institución con orden de realización de angiotomografía computarizada toracoabdominal gatillada con electrocardiograma por distintas indicaciones clínicas. Las mediciones de la AI se realizaron en la fase sistólica, utilizando vistas de cuatro y dos cámaras. Resultados: Se incluyeron un total de 87 pacientes. La edad media fue de 66.4 ± 12.5 años; un 67% de los sujetos fueron hombres. El volumen de la AI indexado por la superficie corporal fue de 48.0 ± 16.6 cm3/m2. Identificamos correlaciones significativas entre las dimensiones de la AI y la edad (p < 0.05). Sin embargo, no se evidenciaron correlaciones significativas entre las dimensiones de la AI y los distintos depósitos de grasa corporal, ya sea totales o regionales. Conclusiones: En este estudio, no identificamos relaciones significativas entre las dimensiones de la AI y los depósitos de grasa corporal globales o regionales.Background and Objectives: The relationship between body fat depots and the left atrial (LA) dimensions has not been fully explored. Our objective is to determine if there is a relationship not only with total body fat depots, but specifically with regional fatty depots. Materials and Methods: It was an observational, retrospective study that included consecutive patients referred to our institution with an order to perform computed tomography angiography triggered by electrocardiogram for different clinical indications. Measurements of the LA were made in the systolic phase, using four and two cameras views. Results: A total of 87 patients were included. The mean age was 66.4 ± 12.5 years; 67% were men. The LA volume indexed by the body surface area was 48.0 ± 16.6 cm3/m2. We identified significant correlations between the LA dimensions and the age (p < 0.05). However, no significant correlations were found between the LA dimensions and the body fat depots, either total or regional. Conclusions: In this study, we did not identify significant relationships between LA dimensions and global or regional body fat depots.Fil: de Zan, Macarena C.. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Carrascosa, Patricia M.. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Reynoso, Exequiel. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Deviggiano, Alejandro. Diagnostico Maipu, Buenos Aires; ArgentinaFil: Deschle, Hector. Diagnostico Maipu, Buenos Aires; ArgentinaFil: 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; Argentin