[Right aortic arch, Kommerell's diverticulum and aberrant left subclavian artery]. / Arco aórtico derecho, divertículo de Kommerell y arteria subclavia izquierda aberrante.

The right aberrant subclavian artery or "arteria lusoria" is the most common anatomical variant of the embryonic development of the aorta and its branches, with a presence in 0.5-2% of the population. Less frequently, a right aortic arch with aberrant left subclavian artery may be present. These anatomical variations should be included in the differential diagnosis of superior mediastinal widening seen on chest radiographs. In this report, we present a right aortic arch with left aberrant subclavian artery dilated at its origin (Kommerell's diverticulum) as a cause of superior mediastinal widening detected incidentally on a chest radiograph.

[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.