A coarse-to-fine approach to prostate boundary segmentation in ultrasound images

BACKGROUND: In this paper a novel method for prostate segmentation in transrectal ultrasound images is presented. METHODS: A segmentation procedure consisting of four main stages is proposed. In the first stage, a locally adaptive contrast enhancement method is used to generate a well-contrasted image. In the second stage, this enhanced image is thresholded to extract an area containing the prostate (or large portions of it). Morphological operators are then applied to obtain a point inside of this area. Afterwards, a Kalman estimator is employed to distinguish the boundary from irrelevant parts (usually caused by shadow) and generate a coarsely segmented version of the prostate. In the third stage, dilation and erosion operators are applied to extract outer and inner boundaries from the coarsely estimated version. Consequently, fuzzy membership functions describing regional and gray-level information are employed to selectively enhance the contrast within the prostate region. In the last stage, the prostate boundary is extracted using strong edges obtained from selectively enhanced image and information from the vicinity of the coarse estimation. RESULTS: A total average similarity of 98.76%(± 0.68) with gold standards was achieved. CONCLUSION: The proposed approach represents a robust and accurate approach to prostate segmentation

Neoliberalism: From New Liberal Philosophy to Anti-Liberal Slogan

In recent years, neoliberalism has become an academic catchphrase. Yet, in contrast to other prominent social science concepts such as democracy, the meaning and proper usage of neoliberalism curiously have elicited little scholarly debate. Based on a content analysis of 148 journal articles published from 1990 to 2004, we document three potentially problematic aspects of neoliberalism’s use: the term is often undefined; it is employed unevenly across ideological divides; and it is used to characterize an excessively broad variety of phenomena. To explain these characteristics, we trace the genesis and evolution of the term neoliberalism throughout several decades of political economy debates. We show that neoliberalism has undergone a striking transformation, from a positive label coined by the German Freiberg School to denote a moderate renovation of classical liberalism, to a normatively negative term associated with radical economic reforms in Pinochet’s Chile. We then present an extension of W. B. Gallie’s framework for analyzing essentially contested concepts to explain why the meaning of neoliberalism is so rarely debated, in contrast to other normatively and politically charged social science terms. We conclude by proposing several ways that the term can regain substantive meaning as a “new liberalism” and be transformed into a more useful analytic tool