[Accuracy of different segmentation methods to quantify cardiac function parameters and left ventricular mass in an animal model]. / Exactitud de distintos métodos de segmentación para cuantificar parámetros de función cardiaca y masa ventricular izquierda en un modelo animal.

OBJECTIVES: To evaluate accuracy of manual, semiautomatic and automatic segmentation methods to quantify cardiac function parameters, volumes, and left ventricular mass. MATERIAL AND METHODS: Ten Goettingen miniature pigs (seven male, three female; mean weight 49.8 kg; SD: 10.65; range: 35-65 kg) were evaluated using a 1.5 Tesla MR scanner and free-breathing SSFP sequences. Short axis images were employed to quantify cardiac parameters. In all animals volumes (end-diastolic volume, end-sisstolic volume, stroke volume), ejection fraction and left ventricular mass was calculated. To quantify these parameters three different segmentation methods (manual, semiautomatic, and automatic) were employed. The correlation of different segmentation methods for each variable was analyzed. RESULTS: No statistically significant differences in left ventricular volume or mass quantification using different segmentation methods was found (p > 0.05). Correlation to estimate ejection fraction and end-diastolic volume was good (r > 0.6) and turned to be excellent for the rest of the variables (r > 0.8). Mean quantification time was less for semiautomatic and automatic methods than for the manual method. CONCLUSIONS: SSFP sequences allow to accurately evaluate cardiac function parameters and left ventricular mass in a large animal model with any of the segmentation method described in this report. Non-manual segmentation methods allow rapid quantification of cardiac parameters.

Exactitud de distintos métodos de segmentación para cuantificar parámetros de función cardiaca y masa ventricular izquierda en un modelo animal / Accuracy of different segmentation methods to quantify cardiac function parameters and left ventricular mass in an animal model

Objetivos. Evaluar la exactitud de los métodos de segmentación manual, semiautomático y automático, para cuantificar parámetros de función cardiaca, volúmenes y masa ventricular izquierda. Material y métodos. Se estudiaron diez cerdos miniatura tipo Goettingen (siete machos y tres hembras; peso medio: 49,8 kg; desviación estándar: 10,65; rango: 35-65 kg) en un equipo de 1,5 Tesla con secuencias SSFP en respiración libre. Se utilizaron las secuencias obtenidas en el eje corto para cuantificar los parámetros cardiacos. En todos los animales se calcularon los volúmenes (volumen telediastólico, volumen telesistólico y volumen latido), la fracción de eyección y la masa miocárdica del ventrículo izquierdo. Para cuantificar estos parámetros se utilizaron tres métodos de segmentación: manual, semiautomático y automático. Se estudió la correlación entre los distintos métodos de segmentación para cada variable. Resultados. No se detectaron diferencias estadísticamente significativas en la cuantificación de volúmenes o masa ventricular izquierda con los distintos métodos de segmentación (p > 0,05). Su correlación fue buena para estimar la FE y el volumen telesistólico (r > 0,6) y excelente para cuantificar el resto de los parámetros (r > 0,8). El tiempo necesario para realizar la cuantificación fue menor para los métodos semiautomático y automático que para el método manual. Conclusiones. Las secuencias SSFP permiten estudiar los parámetros de función cardiaca y masa ventricular izquierda en cerdos miniatura tipo Goettingen con exactitud sin que existan diferencias estadísticamente significativas entre los distintos métodos de segmentación empleados. Los métodos de segmentación no manuales permiten cuantificar los parámetros cardiacos de manera más rápida (p < 0,01)

Objectives. To evaluate accuracy of manual, semiautomatic and automatic segmentation methods to quantify cardiac function parameters, volumes, and left ventricular mass. Material and methods. Ten Goettingen miniature pigs (seven male, three female; mean weight 49.8 kg; SD: 10.65; range: 35-65 kg) were evaluated using a 1.5 Tesla MR scanner and free-breathing SSFP sequences. Short axis images were employed to quantify cardiac parameters. In all animals volumes (end-diastolic volume, end-sisstolic volume, stroke volume), ejection fraction and left ventricular mass was calculated. To quantify these parameters three different segmentation methods (manual, semiautomatic, and automatic) were employed. The correlation of different segmentation methods for each variable was analyzed. Results. No statistically significant differences in left ventricular volume or mass quantification using different segmentation methods was found (p > 0.05). Correlation to estimate ejection fraction and end-diastolic volume was good (r > 0.6) and turned to be excellent for the rest of the variables (r > 0.8). Mean quantification time was less for semiautomatic and automatic methods than for the manual method. Conclusions. SSFP sequences allow to accurately evaluate cardiac function parameters and left ventricular mass in a large animal model with any of the segmentation method described in this report. Non-manual segmentation methods allow rapid quantification of cardiac parameters

Sexual and physical growth in Kerala boys.

One hundred and fifty males in the age group 10-17 years were studied longitudinally for 2 years to determine their physical and pubertal development. The velocity of linear growth, weight gain and pubertal growth velocities were determined. The relation between peak height velocity and genital stages and between genital stages and pubic hair was determined. It is concluded from this study that 86 percent of normal males reach peak height velocity while in G4 and only 5% will not have achieved peak height velocity by the time G5 is reached.

Quantitative estimation of urinary protein excretion by refractometry.

Quantitative estimation of proteinuria done by the refractometric method was compared with that done by the sulphosalycilic acid method and biuret method in 102 urine samples. The analysis of results by students' t test showed no statistically significant difference between the three methods. It is concluded that quantitative estimation of urinary protein excretion by refractometric method is a simple cheap and reliable method and can be performed easily in the outpatient clinic. The instrument is quite handy and can be carried in the pocket.