Within the last years some segmentation algorithms working on 3D echocardiography data have been published. Usually such algorithms have been validated against contours manually drawn within the acquired imaging data. This praxis requires considerable expert knowledge and is time-consuming. We propose a different workflow based on synthetic ultrasound volumes. These volumes can be generated from computed tomography (CT) volumes or a surface models. The echocardiography simulation includes reflection, attenuation, speckle and interference between adjacent receiver elements. Based the synthetic echocardiography volumes we present a tool to validate segmentation algorithms. We illustrate the use of our tool in quantifying the segmentation result for a 3D region-based active contour approach.