Thomas Goldstein

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Total Variation-based regularization, well established for image processing applications such as denoising, was recently introduced for Maximum Penalized Likelihood Estimation (MPLE) as an effective way to estimate nonsmooth probability densities. While the estimates show promise for a variety of applications, the nonlinearity of the regularization leads to(More)
Accurate and fast quantification of myocardial blood flow (MBF) with MR first-pass perfusion imaging techniques on a pixel-by-pixel basis remains difficult due to relatively long calculation times and noise-sensitive algorithms. In this study, Zierler's central volume principle was used to develop an algorithm for the calculation of MBF with few assumptions(More)
Mapping of myocardial blood flow (MBF) with first-pass perfusion imaging is becoming an important tool in the study of coronary artery disease. In this study a wavelet-based denoising method was developed to improve the accuracy of pixel-by-pixel MBF maps. We performed an in vivo study in five stenotic dogs with 70% stenosis in the left coronary arteries.(More)
The alternating direction method of multipliers (ADMM) is a versatile tool for solving a wide range of constrained optimization problems, with differentiable or non-differentiable objective functions. Unfortunately, its performance is highly sensitive to a penalty parameter, which makes ADMM often unreliable and hard to automate for a non-expert user. We(More)
• Emphasis: Large scale distributed and parallel optimization Awards Richard C. DiPrima Prize • Awarded to one person every two years by the Society for Industrial and Applied Mathematics (SIAM) for outstanding research in applied mathematics
Myocardial oxygen extraction fraction (OEF) during hyperemia can be estimated using a double-inversion-recovery-prepared T(2)-weighted black-blood sequence. Severe irregular electrocardiogram (ECG) triggering due to elevated heart rate and/or arrhythmias may render it difficult to adequately suppress the flowing left ventricle blood signal and thus(More)
PURPOSE Myocardial blood volume (MBV) may provide complementary information about myocardial oxygen needs and viability. The aim of this study is to examine a Cardiovascular Magnetic Resonance (CMR) perfusion method to quantify the changes in MBV, in comparison with the radiolabeled 99mTc-Red-Blood-Cell (RBC) method. METHODS Normal mongrel dogs (n=12)(More)
We introduce a new method for location recovery from pair-wise directions that leverages an efficient convex program that comes with exact recovery guarantees, even in the presence of adversarial out-liers. When pairwise directions represent scaled relative positions between pairs of views (estimated for instance with epipolar geometry) our method can be(More)
—The increasing complexity of deep learning ar-chitectures is resulting in training time requiring weeks or even months. This slow training is due in part to " vanishing gradients, " in which the gradients used by back-propagation are extremely large for weights connecting deep layers (layers near the output layer), and extremely small for shallow layers(More)