Análisis de la función ventricular derecha en resonancia magnética cardíaca. Comparación de la cuantificación en los planos eje corto y 4 cámaras / Cardiac magnetic resonance analysis of right ventricular function: comparison of quantification in the short-axis and 4-chamber planes

Objetivo. Comparar los métodos de segmentación del ventrículo derecho en los planos eje corto y 4 cámaras, en los estudios de resonancia magnética cardíaca, y realizar una correlación con el método ecocardiográfico tricuspid annular plane systolic excursion (TAPSE). Material y métodos. Se estudiaron 26 pacientes con diversas enfermedades cardiovasculares con un equipo de resonancia magnética de 1,5 T. Se adquirieron en todos los estudios imágenes en modo cine en eje corto y en 4 cámaras (steady-state free precession, 6 mm de grosor de corte, desde la base al ápex ventricular). En todos los pacientes se cuantificaron los volúmenes telediastólico, telesistólico y la fracción de eyección del ventrículo derecho. A 14 pacientes se les practicó también una ecocardiografía y se calculó la función ventricular derecha (TAPSE), el mismo día que se realizó el estudio de resonancia magnética cardíaca. Resultados. No hubo diferencias estadísticamente significativas en los volúmenes y la función del ventrículo derecho determinados con los 2 métodos de segmentación. La correlación al estimar los volúmenes fue excelente (r > 0,95) y disminuyó levemente para la fracción de eyección (r > 0,84). La correlación entre fracción de eyección del ventrículo derecho y TAPSE fue muy baja (r = 0,2; p < 0,01). Conclusión. Ambos métodos de segmentación ventricular cuantifican adecuadamente la función del ventrículo derecho. La correlación con el método ecocardiográfico es discreta (AU)

Objective. To compare the methods of right ventricle segmentation in the short-axis and 4-chamber planes in cardiac magnetic resonance imaging and to correlate the findings with those of the tricuspid annular plane systolic excursion (TAPSE) method in echocardiography. Material and methods. We used a 1.5 T MRI scanner to study 26 patients with diverse cardiovascular diseases. In all MRI studies, we obtained cine-mode images from the base to the apex in both the short-axis and 4-chamber planes using steady-state free precession sequences and 6 mm thick slices. In all patients, we quantified the end-diastolic volume, end-systolic volume, and the ejection fraction of the right ventricle. On the same day as the cardiac magnetic resonance imaging study, 14 patients also underwent echocardiography with TAPSE calculation of right ventricular function. Results. No statistically significant differences were found in the volumes and function of the right ventricle calculated using the 2 segmentation methods. The correlation between the volume estimations by the two segmentation methods was excellent (r = 0,95); the correlation for the ejection fraction was slightly lower (r = 0,8). The correlation between the cardiac magnetic resonance imaging estimate of right ventricular ejection fraction and TAPSE was very low (r = 0,2, P < .01). Conclusion. Both ventricular segmentation methods quantify right ventricular function adequately. The correlation with the echocardiographic method is low (AU)

Cardiac magnetic resonance analysis of right ventricular function: comparison of quantification in the short-axis and 4-chamber planes.

OBJECTIVE: To compare the methods of right ventricle segmentation in the short-axis and 4-chamber planes in cardiac magnetic resonance imaging and to correlate the findings with those of the tricuspid annular plane systolic excursion (TAPSE) method in echocardiography. MATERIAL AND METHODS: We used a 1.5T MRI scanner to study 26 patients with diverse cardiovascular diseases. In all MRI studies, we obtained cine-mode images from the base to the apex in both the short-axis and 4-chamber planes using steady-state free precession sequences and 6mm thick slices. In all patients, we quantified the end-diastolic volume, end-systolic volume, and the ejection fraction of the right ventricle. On the same day as the cardiac magnetic resonance imaging study, 14 patients also underwent echocardiography with TAPSE calculation of right ventricular function. RESULTS: No statistically significant differences were found in the volumes and function of the right ventricle calculated using the 2 segmentation methods. The correlation between the volume estimations by the two segmentation methods was excellent (r=0,95); the correlation for the ejection fraction was slightly lower (r=0,8). The correlation between the cardiac magnetic resonance imaging estimate of right ventricular ejection fraction and TAPSE was very low (r=0,2, P<.01). CONCLUSION: Both ventricular segmentation methods quantify right ventricular function adequately. The correlation with the echocardiographic method is low.

[Semiautomatic quantification of left and right ventricular function in cardiac magnetic resonance imaging: a preliminary study]. / Cuantificación semiautomática de la función ventricular izquierda y derecha en resonancia magnética cardíaca. Estudio preliminar.

OBJECTIVES: The aim of this study was to compare a semiautomatic segmentation method to quantify the function of both ventricles in magnetic resonance imaging (MRI) with the manual tracing method. MATERIAL AND METHODS: We examined 17 patients with diverse cardiovascular diseases on a 1.5 Tesla MRI unit (Magnetom Symphony Quantum; Siemens Medical Systems, Erlangen, Germany) using the following parameters: maximum gradient, 30 mT/m; and slew rate, 125 T/m/s. In all studies, we acquired images in cine mode in the short axis (SSFP, 6mm slice thickness, from the base to the ventricular apex) with breath holding. To reduce the user interaction, we used only one image per patient to initiate the semiautomatic method. The semiautomatic method was based on a specifically designed algorithm of regional growth and border detection. We quantified the end-diastolic volume (EDV), end-systolic volume (ESV), and the ejection fraction (EF) for both ventricles in all patients. RESULTS: No significant differences between the two segmentation techniques were found in the quantification of either ventricle (p>0.05). The difference in the volumes, although nearly significant, are clinically irrelevant. The correlation for the estimation of left ventricular function was excellent (r>0.9), and the correlation for the estimation of right ventricular function was good (r>0.7). CONCLUSIONS: Our semiautomatic segmentation method enables the function of both ventricles to be quantified as accurately as the conventional method.

[Automatic detection of pulmonary nodules on computed tomography: a preliminary study]. / Detección automática de nódulos pulmonares en tomografía computarizada.Un estudio preliminar.

OBJECTIVES: Recent years have seen growing interest in the development of algorithms for computer-assisted diagnosis (CAD) for the detection of pulmonary nodules on both plain-film radiographs and computed tomography (CT) studies. The purpose of CAD algorithms in this context is to alert radiologists to suspicious radioopacities that might represent cancer in the images. We are developing a CAD system for the detection of pulmonary nodules on helical CT images. MATERIAL AND METHODS: We collected cases of patients with pulmonary nodules examined with helical CT. A total of 64 nodules, including both calcified and noncalcified lesions, ranging from 3 to 30 mm in diameter were included in the study. Studies were acquired on one 4-slice and one 64-slice CT scanners. Three chest radiologists at two institutions interpreted the studies to determine whether pulmonary nodules were present. We calculated the sensitivity and the number of false positives per image to evaluate the CAD system. RESULTS: We have developed and evaluated an algorithm for the automatic detection of pulmonary nodules on CT images. For a sensitivity of 76%, the false-positive rate was 1.3 per image. CONCLUSIONS: Our preliminary results suggest that the system might be useful for radiologists in the detection of pulmonary nodules on helical CT images.