202,301 research outputs found


    Get PDF


    Get PDF

    ScarGAN: Chained Generative Adversarial Networks to Simulate Pathological Tissue on Cardiovascular MR Scans

    Full text link
    Medical images with specific pathologies are scarce, but a large amount of data is usually required for a deep convolutional neural network (DCNN) to achieve good accuracy. We consider the problem of segmenting the left ventricular (LV) myocardium on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) scans of which only some of the scans have scar tissue. We propose ScarGAN to simulate scar tissue on healthy myocardium using chained generative adversarial networks (GAN). Our novel approach factorizes the simulation process into 3 steps: 1) a mask generator to simulate the shape of the scar tissue; 2) a domain-specific heuristic to produce the initial simulated scar tissue from the simulated shape; 3) a refining generator to add details to the simulated scar tissue. Unlike other approaches that generate samples from scratch, we simulate scar tissue on normal scans resulting in highly realistic samples. We show that experienced radiologists are unable to distinguish between real and simulated scar tissue. Training a U-Net with additional scans with scar tissue simulated by ScarGAN increases the percentage of scar pixels correctly included in LV myocardium prediction from 75.9% to 80.5%.Comment: 12 pages, 5 figures. To appear in MICCAI DLMIA 201

    Experimental phase-space-based optical amplification of scar modes

    Get PDF
    Waves billiard which are chaotic in the geometrical limit are known to support non-generic spatially localized modes called scar modes. The interaction of the scar modes with gain has been recently investigated in optics in micro-cavity lasers and vertically-cavity surface-emitting lasers. Exploiting the localization properties of scar modes in their wave analogous phase space representation, we report experimental results of scar modes selection by gain in a doped D-shaped optical fiber

    Albrecht Durer and the Lutheran Reformation

    Get PDF
    This dissertation is a study of Albrecht Dürer\u27s life and work with a theologioa1 interest. This is in no way a complete discussion of the artist\u27s life and works. The selection of works treated in chapter four is not a good cross section of his drawings, woodcuts. copper engravings, etchings, and paintings. They are a careful selection of his works of art showing how he gradually employed true Christian or Biblical teaching in his religious subjects. The author endeavors to show in this paper that Albrecht Dürer made a contribution to the work of Martin Luther and his associates as a preparatory figure to the reform movement and how later the work of Martin Luther influenced the great German artist

    Selective amplification of scars in a chaotic optical fiber

    Get PDF
    In this letter we propose an original mechanism to select scar modes through coherent gain amplification in a multimode D-shaped fiber. More precisely, we numerically demonstrate how scar modes can be amplified by positioning a gain region in the vicinity of specific points of a short periodic orbit known to give rise to scar modes

    The correlation between histopathological and ultrasound findings regarding Cesarean section scars – A three-year survey study

    Get PDF
    The cesarean operation represents a major surgery, with a higher risk of postoperative complications and longer postoperative recovery than vaginal delivery. Due to the increasing frequency of cesarean sections, the ultrasound imaging of the uterine scar has become a particularly useful tool in identifying its potential long-term complications. This should be done pre-conceptively and quarterly or whenever necessary during pregnancy. Currently, there are only few histopathological studies on the uterine scar, trying to assess the myometrial repair and certain factors that influence the quality of the scar. The study was performed on a batch of 123 patients with previous C-sections, with multiple ultrasound exams during pregnancy and post-operative pathologic evaluation of the uterine scar in order to assess the possibility of a new prognostic score by correlating these two factors. Our study found solid evidence related to possible correlations between histopathological and ultrasound data on the cesarean section scar, which could lead to a possible predictive algorithm with implications for both prognostic and therapeutic fields