Fases de reconstrucción y exactitud de la tomografía computarizada para cuantificar la función y masa ventricular izquierda / Accuracy of different reconstruction intervals to quantify left ventricular function and mass in cardiac computed tomography examinations

Objetivo. Comparar los parámetros de función y masa ventricular izquierda (VI) obtenidos con reconstrucciones realizadas en intervalos del 5 y 10% del ciclo cardiaco en pacientes con trasplante cardiaco y determinar su exactitud respecto a la resonancia magnética (RM). Material y métodos. Se incluyeron 23 trasplantados cardiacos consecutivos (21 varones; edad media 60±11,7 años) a los que se realizó un estudio cardiaco mediante tomografía computarizada (TC) de doble fuente (TCDF) y RM. Se compararon los parámetros de función y masa VI obtenidos de las imágenes de TCDF reconstruidas en intervalos del 5% (0-95%) y 10% (0-90%) del ciclo cardiaco respecto a los estimados mediante RM. Los parámetros se calcularon con un software de segmentación semiautomático en TCDF y trazando los contornos manualmente en RM. En todos los individuos se estimaron la fracción de eyección (FE), los volúmenes telediastólico (VTD), telesistólico (VTS), latido (VL) y la masa miocárdica. Resultados. La cuantificación de los parámetros de función VI mediante TCDF no mostró diferencias estadísticamente significativas según el número de fases reconstruidas (p>0,05). Respecto a la RM se observó una ligera sobreestimación de VTD, VTS y masa VI al utilizar tanto intervalos del 5% (diferencia media: 11,5±25,1ml; 6,8±10,9ml, y 28,3±21,6g, respectivamente) como 10% (diferencia media: 15,3±26,3ml; 7,4±11,5ml; 29,3±18,7g, respectivamente), con diferencias no significativas para la FE y el VL. Conclusión. En pacientes con trasplante cardiaco la TCDF es una técnica que permite cuantificar la función y la masa VI prácticamente con la misma exactitud que la RM, incluso utilizando intervalos de reconstrucción del 10% (AU)

Purpose. To compare the accuracy of cardiac dual-source CT (DSCT) reconstructions obtained at 5% and 10% of the cardiac cycle and MRI for quantifying global left ventricular (LV) function and mass in heart transplant recipients. Material and methods. We prospectively included 23 heart transplant recipients (21 male, mean age 60±11.7 years) who underwent cardiac DSCT and MRI examinations. We compared LV parameters on cardiac DSCT reconstructions obtained at 5% (0%-95%) and 10% (0%-90%) intervals of the cardiac cycle and on double-oblique short-axis MR images. We determined ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial mass using commercially available semiautomated segmentation analysis software for DSCT datasets and conventional manual contour tracing for MR studies. Results. Using different reconstruction intervals to quantify LV parameters at DSCT resulted in non-significant differences (P>.05). Compared to MRI, DSCT slightly overestimated LV-EDV, ESV, and mass when both 5% (11.5±25.1ml, 6.8±10.9ml, and 28.3±21.6g, respectively) and 10% (mean difference 15.3±26.3ml, 7.4±11.5ml, and 29.3±18.7g, respectively) reconstruction intervals were used. DSCT and MRI estimates of EF and SV were not significantly different. Conclusion. In heart transplant recipients, DSCT allows reliable quantification of LV function and mass compared with MRI, even using 10% interval reconstructions (AU)

Dual source CT: state of the art in the depiction of coronary arteries anatomy, anatomical variants and myocardial segments.

Cardiovascular disease is the leading cause of death in adults in western countries. Coronary angiography remains the gold standard for the diagnosis of coronary artery disease, a procedure that carries risks. Nowadays, a significant number of the coronary angiographies performed every year are only diagnostic. Multidetector computed tomography (MDCT) allows non-invasive evaluation of coronary arteries. It is a continuously developing technique, and actually the top technology is represented by Dual Source CT. This scanner of new conception permits an improvement in image quality, and visualization of distal vessels and small collateral branches. The aim of our work is to illustrate the actual state of the art in non-invasive coronary arteries evaluation represented by Dual Source CT, presenting images of coronary arteries normal anatomy, anatomical variants and myocardial segment.

Accuracy of different reconstruction intervals to quantify left ventricular function and mass in cardiac computed tomography examinations.

PURPOSE: To compare the accuracy of cardiac dual-source CT (DSCT) reconstructions obtained at 5% and 10% of the cardiac cycle and MRI for quantifying global left ventricular (LV) function and mass in heart transplant recipients. MATERIAL AND METHODS: We prospectively included 23 heart transplant recipients (21 male, mean age 60±11.7 years) who underwent cardiac DSCT and MRI examinations. We compared LV parameters on cardiac DSCT reconstructions obtained at 5% (0%-95%) and 10% (0%-90%) intervals of the cardiac cycle and on double-oblique short-axis MR images. We determined ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial mass using commercially available semiautomated segmentation analysis software for DSCT datasets and conventional manual contour tracing for MR studies. RESULTS: Using different reconstruction intervals to quantify LV parameters at DSCT resulted in non-significant differences (P>.05). Compared to MRI, DSCT slightly overestimated LV-EDV, ESV, and mass when both 5% (11.5±25.1ml, 6.8±10.9ml, and 28.3±21.6g, respectively) and 10% (mean difference 15.3±26.3ml, 7.4±11.5ml, and 29.3±18.7g, respectively) reconstruction intervals were used. DSCT and MRI estimates of EF and SV were not significantly different. CONCLUSION: In heart transplant recipients, DSCT allows reliable quantification of LV function and mass compared with MRI, even using 10% interval reconstructions.

Bronquio traqueal congénito / No disponible

No disponible

Tomografía computarizada de doble fuente en pacientes hospitalizados con dolor torácico de etiología incierta / Dual-source computed tomography in inpatients with atypical chest pain

Objetivo: Valorar la utilidad de la tomografía computarizada de doble fuente (TCDF) como técnica diagnóstica en pacientes hospitalizados con dolor torácico atípico de etiología incierta. Material y métodos: Se incluyeron 41 sujetos consecutivos hospitalizados en nuestro centro (25 varones, 16 mujeres; edad media 55,6±17,39 años) con dolor torácico atípico sin causa clínicamente reconocible en los que se indicó un estudio de TC para filiar su etiología. Los estudios se realizaron en un equipo TCDF con sincronización ECG retrospectiva tras administrar 120 ml de contraste iodado a 4 ml/s utilizando la técnica de bolus tracking. Los estudios fueron analizados por 2 observadores de forma consensuada. Resultados: Las exploraciones fueron diagnósticas en todos los pacientes. Se hallaron 5 casos de tromboembolismo pulmonar y 2 de patología aórtica (1 úlcera aórtica y 1 aneurisma sacular). Se objetivaron anomalías en las arterias coronarias en 15 sujetos, 2 de los cuales presentaron estenosis >50%. Como hallazgos extracardiovasculares se diagnosticaron 11 casos de neumonía, 1 sarcoidosis y 1 carcinoma no microcítico de pulmón. Además, se observó derrame pleural en 4 sujetos y derrame pericárdico en otros 4. El resultado fue negativo en un 22% de los sujetos. La evolución fue favorable en todos los pacientes y ninguno volvió a acudir por persistencia del dolor o episodio de dolor torácico de nueva aparición durante el período de seguimiento. Conclusión: La TCDF es una técnica útil para filiar la etiología y descartar las causas potencialmente más graves de dolor torácico en pacientes hospitalizados (AU)

Objective: To evaluate the potential usefulness of dual-source CT (DSCT) in the diagnostic work-up of inpatients with atypical chest pain of unknown etiology. Material and methods: Forty-one consecutive inpatients (25 male, 16 female; mean age 55.6±17.39 years) with atypical chest pain underwent DSCT to determine the cause of pain. Images were acquired with retrospective ECG gating after the administration of 120ml of iodinated contrast medium at 4ml/s using the bolus tracking technique. Two readers analyzed the images in consensus. Results: DSCT was diagnostic in all patients. We detected pulmonary embolisms in five patients and aortic disease in two (one aortic ulcer and one sacular aneurysm). Anomalies of the coronary arteries were depicted in 15 patients, two of whom presented luminal stenosis >50%. Extracardiovascular findings at DSCT included pneumonia in eleven patients, sarcoidosis in one, and non-small cell lung carcinoma in one. Pleural effusion was detected in four patients and pericardial effusion in another four. No pathological findings were observed in 22% of subjects. Evolution was favorable in all patients. No patients were readmitted for persistent pain or new onset of acute chest pain during the follow-up period. Conclusion: DSCT can rule out most life-threatening clinical conditions that cause chest pain and is useful in determining the cause of chest pain in inpatients (AU)

[Dual-source computed tomography in inpatients with atypical chest pain]. / Tomografía computarizada de doble fuente en pacientes hospitalizados con dolor torácico de etiología incierta.

OBJECTIVE: To evaluate the potential usefulness of dual-source CT (DSCT) in the diagnostic work-up of inpatients with atypical chest pain of unknown etiology. MATERIAL AND METHODS: Forty-one consecutive inpatients (25 male, 16 female; mean age 55.6+/-17.39 years) with atypical chest pain underwent DSCT to determine the cause of pain. Images were acquired with retrospective ECG gating after the administration of 120ml of iodinated contrast medium at 4ml/s using the bolus tracking technique. Two readers analyzed the images in consensus. RESULTS: DSCT was diagnostic in all patients. We detected pulmonary embolisms in five patients and aortic disease in two (one aortic ulcer and one sacular aneurysm). Anomalies of the coronary arteries were depicted in 15 patients, two of whom presented luminal stenosis >50%. Extracardiovascular findings at DSCT included pneumonia in eleven patients, sarcoidosis in one, and non-small cell lung carcinoma in one. Pleural effusion was detected in four patients and pericardial effusion in another four. No pathological findings were observed in 22% of subjects. Evolution was favorable in all patients. No patients were readmitted for persistent pain or new onset of acute chest pain during the follow-up period. CONCLUSION: DSCT can rule out most life-threatening clinical conditions that cause chest pain and is useful in determining the cause of chest pain in inpatients.

Coronariografía mediante tomografía computarizada de doble fuente: calidad de imagen e intervalo de reconstrucción óptimo / Dual-source CT coronary angiography: image quality and optimal reconstruction interval

Objetivo: evaluar prospectivamente la relación entre frecuencia cardíaca y calidad de imagen, y determinar el intervalo de reconstrucción óptimo para las arterias coronarias en estudios de tomografía computarizada de doble fuente (TCDF). Material y métodos: se analizaron 28 sujetos consecutivos en que se realizó coronariografía mediante TCDF (Somatom Definition, Siemens). Las imágenes se reconstruyeron a lo largo del ciclo cardíaco en intervalos del 5% R-R. Dos observadores independientes evaluaron la calidad diagnóstica de las imágenes para las arterias coronarias (izquierda, circunfleja y derecha) (1=no evaluable; 4=calidad excelente). Resultados: la frecuencia cardíaca media de los pacientes fue 73,1±14,8lpm (rango, 49–107lpm). En el mejor intervalo de reconstrucción se obtuvo excelente calidad de imagen (4 puntos) en el 98,8% (83/84) de las arterias coronarias. La concordancia interobservador para la puntuación de calidad de imagen y selección del intervalo de reconstrucción óptimo fue muy buena (k=0,77 y k=0,86). La puntuación media de calidad para todo el árbol coronario fue 2,84±0,31. No se observó correlación entre la frecuencia cardíaca media y la calidad de la imagen de las arterias coronarias (r=0,108). No hubo diferencias estadísticamente significativas al comparar la calidad de imagen obtenida en las reconstrucciones sistólicas y diastólicas en cada paciente. Conclusiones: la TCDF permite obtener coronariografías de excelente calidad diagnóstica independientemente de la frecuencia cardíaca. Las reconstrucciones se pueden realizar tanto en sístole como en diástole sin que hayan diferencias estadísticamente significativas en la calidad, incluso con frecuencias cardíacas elevadase (AU)

Objective: To evaluate the effect of average heart rate on the quality of images of the coronary arteries and to determine the optimal reconstruction interval in nonselected patients undergoing DSCT coronary imaging. Materials and methods: We studied 28 consecutive subjects (26 men, 2 women; mean age 60±12 years) undergoing contrast-enhanced DSCT (Somatom Definition, Siemens) coronary angiography. Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers assessed the image quality of the whole coronary tree and of each coronary artery using a four-point scale (1: impossible to evaluate, 4: excellent quality). Results: Mean heart rate during scanning was 73.1±14.8bpm (range, 49–107bpm). In the best reconstruction interval, excellent diagnostic image quality (score 4) was achieved for 98.8% (83/84) of coronary arteries. Very good interobserver agreement was observed for image quality rating (k=0.77) and for selection of the optimal reconstruction interval (k=0.86). Mean image quality score for the whole coronary tree was 2.84±0.31. No significant correlation was found between the average heart rate and the mean quality scores (r=0.108). No significant differences were found in the quality of images of the coronary arteries in systolic and diastolic reconstructions in each patient. Conclusions: DSCT makes it possible to obtain excellent coronary angiograms independent of the heart rate. Reconstructions can be obtained in either the diastolic or systolic phase without significant differences in image quality, even at high heart rates (AU)

[Global evaluation of the heart in heart transplant recipients using dual-source computed tomography]. / Valoración global del corazón en el paciente con transplante cardiaco mediante tomografía computarizada de doble fuente.

In routine clinical practice surveillance of heart transplant recipients is usually performed using echocardiography and conventional coronary angiography. The latter permits diagnosis and follow-up of coronary allograft vasculopathy. However, this procedure is invasive and is not free of complications. Conventional multislice computed tomography (MSCT) has been shown to be a useful non-invasive tool for ruling out coronary artery disease and evaluating cardiac function. However, due to its limited temporal resolution betablocker administration is required, and its usefulness in certain patient populations with restricted response to this medication, such as heart transplant recipients, may therefore be limited. Dual-source CT (DSCT) allows evaluation of the coronary arteries in all individuals independent of their heart rate. In the case presented here, we demonstrate that DSCT may be useful for evaluating cardiac function and ruling out coronary allograft vasculopathy in heart transplant recipients.

Cuantificación de la función y masa ventricular izquierda mediante tomografía computarizada de doble fuente / Quantification of left ventricular function and mass in dual-source CT (DSCT)

Objetivos Evaluar la reproducibilidad interobservador para cuantificar la función y masa ventricular izquierda (VI) y valorar la exactitud para cuantificar estos parámetros utilizando un software comercial con respecto a la segmentación manual convencional. Material y métodos: Se incluyeron 20 sujetos consecutivos con estudio cardíaco por tomografía computarizada de doble fuente (TCDF) y sincronización electrocardiográfica retrospectiva. Se realizaron 2 reconstrucciones multifásicas en intervalos del 5% del ciclo R-R. La función y masa del VI la cuantificaron 2 observadores independientes que dibujaron manualmente los contornos endo y epicárdicos y utilizaron un software comercial que emplea un método de segmentación semiautomático. Se analizaron la correlación entre ambos observadores, la exactitud de los distintos métodos de segmentación y el tiempo necesario para cuantificar estos parámetros. Resultados La correlación interobservador para cuantificar los parámetros de función y masa VI fue excelente (r>0,94; p<0,05). Los métodos de segmentación manual y semiautomático no mostraron diferencias estadísticamente significativas para estimar la función VI (p>0,05). Con el método semiautomático la estimación de la masa VI fue significativamente superior que al utilizar la segmentación manual (diferencia media 29,45±1,64 g; p<0,05). Para calcular estos parámetros se requirió significativamente menos tiempo con el software comercial (248,85±99,8s) que con el trazado manual (452,7±73,92s) (p<0,05). Conclusiones La reproducibilidad interobservador para cuantificar la función y la masa VI mediante TCDF es excelente. Aunque tiende a sobrestimar la masa miocárdica, el software comercial permite cuantificar los parámetros cardíacos con la misma exactitud que la segmentación manual en la mitad de tiempo (AU)

Objectives To evaluate the interobserver agreement in quantifying left ventricular function and mass and to assess the accuracy of conventional manual contour tracing compared to semiautomatic segmentation analysis software. Material and methods Twenty consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Two different multiphase image reconstructions were done in 5% steps throughout the entire cardiac cycle (0¿95% of the R-R interval) with effective slice thickness of 1mm in the axial plane and 8mm in the short-axis orientation. Left ventricular function and mass were calculated by two independent observers, tracing endocardial and epicardial borders manually and using a semiautomatic software tool (Circulation II, Siemens). Ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), cardiac output (CO), and myocardial mass were evaluated by two independent observers blind to each other's assessments. The interobserver agreement and the reliability of the different segmentation methods were calculated. The time required for manual contouring and semiautomatic contour tracing was also registered. Results We found an excellent correlation (r>0.94; p<0.05) between the two independent observers for the quantification of left ventricular function and mass. Left ventricular functional parameters derived from semiautomatic contour software and conventional manual tracing method were not significantly different (p>0.05). The semiautomatic contour detection algorithm overestimated LV mass significantly compared with the manual contouring method (mean difference 29.45±1.64g; p<0.05). The time needed to calculate these parameters with the semiautomatic tool was significantly lower (248.85±99.8s) than with manual contouring (452.7±73.92s) (p<0.05). Conclusions (..) (AU)

Valoración global del corazón en el paciente con transplante cardiaco mediante tomografía computarizada de doble fuente / Global evaluation of the heart in heart transplant recipients using dual-source computed tomography

La ecocardiografía y la coronariografía convencionalson las dos técnicas empleadas en la práctica clínicapara el seguimiento de los pacientes con transplantecardiaco. La coronariografía permite diagnosticar lavasculopatía del injerto, pero se trata de un procedimientoinvasivo no exento de complicaciones. La tomografíacomputarizada multicorte convencional esuna técnica no invasiva útil para descartar enfermedadcoronaria y estudiar la función cardiaca. Sin embargo,debido a su resolución temporal es necesario administrarfármacos betabloqueantes por lo que su utilidad enlos pacientes con escasa respuesta a esta medicación,como los transplantados cardiacos, es limitada. La TCde doble fuente permite estudiar las arterias coronariasen todos los individuos con independencia de su frecuenciacardiaca. En el caso que se presenta se demuestra,además, que puede ser una técnica útil para valorarla función y descartar la vasculopatía del injerto en lospacientes con transplante cardiaco(AU)

In routine clinical practice surveillance of hearttransplant recipients is usually performed using echocardiographyand conventional coronary angiography. Thelatter permits diagnosis and follow-up of coronary allograftvasculopathy. However, this procedure is invasiveand is not free of complications. Conventional multislicecomputed tomography (MSCT) has been shown to be auseful non-invasive tool for ruling out coronary arterydisease and evaluating cardiac function. However, dueto its limited temporal resolution betablocker administrationis required, and its usefulness in certain patientpopulations with restricted response to this medication,such as heart transplant recipients, may therefore belimited. Dual-source CT (DSCT) allows evaluation of thecoronary arteries in all individuals independent of theirheart rate. In the case presented here, we demonstratethat DSCT may be useful for evaluating cardiac functionand ruling out coronary allograft vasculopathy in hearttransplant recipients(AU)

[Quantification of left ventricular function and mass in dual-source CT (DSCT).]. / Cuantificación de la función y masa ventricular izquierda mediante tomografía computarizada de doble fuente.

OBJECTIVES: To evaluate the interobserver agreement in quantifying left ventricular function and mass and to assess the accuracy of conventional manual contour tracing compared to semiautomatic segmentation analysis software. MATERIAL AND METHODS: Twenty consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Two different multiphase image reconstructions were done in 5% steps throughout the entire cardiac cycle (0-95% of the R-R interval) with effective slice thickness of 1mm in the axial plane and 8mm in the short-axis orientation. Left ventricular function and mass were calculated by two independent observers, tracing endocardial and epicardial borders manually and using a semiautomatic software tool (Circulation II, Siemens). Ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), cardiac output (CO), and myocardial mass were evaluated by two independent observers blind to each other's assessments. The interobserver agreement and the reliability of the different segmentation methods were calculated. The time required for manual contouring and semiautomatic contour tracing was also registered. RESULTS: We found an excellent correlation (r>0.94; p<0.05) between the two independent observers for the quantification of left ventricular function and mass. Left ventricular functional parameters derived from semiautomatic contour software and conventional manual tracing method were not significantly different (p>0.05). The semiautomatic contour detection algorithm overestimated LV mass significantly compared with the manual contouring method (mean difference 29.45+/-1.64g; p<0.05). The time needed to calculate these parameters with the semiautomatic tool was significantly lower (248.85+/-99.8s) than with manual contouring (452.7+/-73.92s) (p<0.05). CONCLUSIONS: Interobserver agreement for quantifying left ventricular function and mass using DSCT is excellent. Despite overestimating left ventricular mass, the semiautomatic software tool allows cardíac parameters to be quantified with the same reliability as the conventional manual method in half the time.

[Dual-source CT coronary angiography: image quality and optimal reconstruction interval]. / Coronariografía mediante tomografía computarizada de doble fuente: calidad de imagen e intervalo de reconstrucción óptimo.

OBJECTIVE: To evaluate the effect of average heart rate on the quality of images of the coronary arteries and to determine the optimal reconstruction interval in nonselected patients undergoing DSCT coronary imaging. MATERIALS AND METHODS: We studied 28 consecutive subjects (26 men, 2 women; mean age 60+/-12 years) undergoing contrast-enhanced DSCT (Somatom Definition, Siemens) coronary angiography. Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers assessed the image quality of the whole coronary tree and of each coronary artery using a four-point scale (1: impossible to evaluate, 4: excellent quality). RESULTS: Mean heart rate during scanning was 73.1+/-14.8 bpm (range, 49-107 bpm). In the best reconstruction interval, excellent diagnostic image quality (score 4) was achieved for 98.8% (83/84) of coronary arteries. Very good interobserver agreement was observed for image quality rating (kappa=0.77) and for selection of the optimal reconstruction interval (kappa=0.86). Mean image quality score for the whole coronary tree was 2.84+/-0.31. No significant correlation was found between the average heart rate and the mean quality scores (r=0.108). No significant differences were found in the quality of images of the coronary arteries in systolic and diastolic reconstructions in each patient. CONCLUSIONS: DSCT makes it possible to obtain excellent coronary angiograms independent of the heart rate. Reconstructions can be obtained in either the diastolic or systolic phase without significant differences in image quality, even at high heart rates.

Coronariografía por tomografía computarizada de doble fuente / No disponible

La tomografía computarizada multicorte (TCMC) permite estudiar las arterias coronarias de forma no invasiva. A pesar de la elevada resolución espacial y temporal de los equipos de sesenta y cuatro cortes (TCMC- 64) esta técnica no se encuentra exenta de limitaciones. La tomografía computarizada de doble fuente (TCDF) permite estudiar las arterias coronarias con gran calidad diagnóstica en todos los sujetos independientemente de su frecuencia cardiaca sin necesidad, por tanto, de emplear betabloqueantes. En este trabajo se describen los estudios por TCDF de tres pacientes con elevada frecuencia cardiaca y gran variabilidad del ritmo. Se demuestra la utilidad de esta técnica para obtener estudios de excelente calidad diagnóstica en casos en que la coronariografía por TCMC-64 convencional presenta limitaciones

Multidetector computed tomography (MDCT) has been demonstrated to be a very useful technique to non-invasively study coronary arteries. Despite the high spatial and temporal resolution of 64-slice MDCT scanners, this technique has several limitations. Dual-source computed tomography (DSCT) allows to study coronary arteries with excellent diagnostic quality in all subjects independent of the heart rate, thus avoiding the use of beta-blockers. In this article DSCT studies from three subjects with elevated heart rate and irregular heart rhythm are described. Usefulness of this technique to obtain studies of excellent quality in cases in which conventional 64-row-MDCT might present limitations is emphasized

Lesiones traqueales focales. A propósito de un caso / No disponible

Presentamos un caso de carcinoma adenoide quístico de tráquea demostrado mediante TC multidetector de 64 coronas, PET-TC, y correlación anatomopatológica, en un paciente con hemoptisis. En este artículo revisamos el diagnóstico diferencial de las lesiones traqueales únicas focales mediante tomografía computarizada (TC). Las técnicas de imagen permitieron el diagnóstico e infravaloraron la invasión de la pared traqueal en este caso, confi rmada con posterioridad mediante el estudio histológico

We present a case of adenoid cystic tracheal carcinoma detected by computerized tomography (64-MDCT) with cyto-histological correlation in a patient with hemoptysis. In this article we review the differential diagnosis of solitary focal tracheal lesions as they appear in computerized tomography (CT). In this case, image methods suggested the diagnosis but underestimated the tracheal wall invasion, which was established by histologycal examination of the resected tumor

[Dual-source CT coronary angiography]. / Coronariografía por tomografía computarizada de doble fuente.

Multidetector computed tomography (MDCT) has been demonstrated to be a very useful technique to non-invasively study coronary arteries. Despite the high spatial and temporal resolution of 64-slice MDCT scanners, this technique has several limitations. Dual-source computed tomography (DSCT) allows to study coronary arteries with excellent diagnostic quality in all subjects independent of the heart rate, thus avoiding the use of beta-blockers. In this article DSCT studies from three subjects with elevated heart rate and irregular heart rhythm are described. Usefulness of this technique to obtain studies of excellent quality in cases in which conventional 64-row-MDCT might present limitations is emphasized.

[Solitary focal tracheal lesions. A case report]. / Lesiones traqueales focales. A propósito de un caso.

We present a case of adenoid cystic tracheal carcinoma detected by computerized tomography (64-MDCT) with cyto-histological correlation in a patient with hemoptysis. In this article we review the differential diagnosis of solitary focal tracheal lesions as they appear in computerized tomography (CT). In this case, image methods suggested the diagnosis but underestimated the tracheal wall invasion, which was established by histologycal examination of the resected tumor.

Pathogenic Yersinia enterocolitica strains increase the outer membrane permeability in response to environmental stimuli by modulating lipopolysaccharide fluidity and lipid A structure.

Pathogenic biotypes of Yersinia enterocolitica (serotypes O:3, O:8, O:9, and O:13), but not environmental biotypes (serotypes O:5, O:6, O:7,8, and O:7,8,13,19), increased their permeability to hydrophobic probes when they were grown at pH 5.5 or in EGTA-supplemented (Ca(2+)-restricted) media at 37 degrees C. A similar observation was also made when representative strains of serotypes O:8 and O:5 were tested after brief contact with human monocytes. The increase in permeability was independent of the virulence plasmid. The role of lipopolysaccharide (LPS) in this phenomenon was examined by using Y. enterocolitica serotype O:8. LPS aggregates of bacteria grown in acidic or EGTA-supplemented broth took up more N-phenylnaphthylamine than LPS aggregates of bacteria grown in standard broth and also showed a marked increase in acyl chain fluidity which correlated with permeability, as determined by measurements obtained in the presence of hydrophobic dyes. No significant changes in O-antigen polymerization were observed, but lipid A acylation changed depending on the growth conditions. In standard medium at 37 degrees C, there were hexa-, penta-, and tetraacyl lipid A forms, and the pentaacyl form was dominant. The amount of tetraacyl lipid A increased in EGTA-supplemented and acidic media, and hexaacyl lipid A almost disappeared under the latter conditions. Our results suggest that pathogenic Y. enterocolitica strains modulate lipid A acylation coordinately with expression of virulence proteins, thus reducing LPS packing and increasing outer membrane permeability. The changes in permeability, LPS acyl chain fluidity, and lipid A acylation in pathogenic Y. enterocolitica strains approximate the characteristics in Yersinia pseudotuberculosis and Yersinia pestis and suggest that there is a common outer membrane pattern associated with pathogenicity.