Objective. To demonstrate a novel approach of compensating overexposure artifacts in CT scans of the knees without attaching any supporting appliances to the patient. C-Arm CT systems offer the opportunity to perform weight-bearing knee scans on standing patients to diagnose diseases like osteoarthritis.
View Article and Find Full Text PDFIn this paper, we propose a multi-sensor super-resolution framework for hybrid imaging to super-resolve data from one modality by taking advantage of additional guidance images of a complementary modality. This concept is applied to hybrid 3-D range imaging in image-guided surgery, where high-quality photometric data is exploited to enhance range images of low spatial resolution. We formulate super-resolution based on the maximum a-posteriori (MAP) principle and reconstruct high-resolution range data from multiple low-resolution frames and complementary photometric information.
View Article and Find Full Text PDFInt J Comput Assist Radiol Surg
May 2015
Purpose: During autopsy, forensic pathologists today mostly rely on visible indication, tactile perception and experience to determine the cause of death. Although computed tomography (CT) data is often available for the bodies under examination, these data are rarely used due to the lack of radiological workstations in the pathological suite. The data may prevent the forensic pathologist from damaging evidence by allowing him to associate, for example, external wounds to internal injuries.
View Article and Find Full Text PDFMed Image Comput Comput Assist Interv
February 2014
Minimally invasive procedures are of growing importance in modern surgery. Navigation and orientation are major issues during these interventions as conventional endoscopes only cover a limited field of view. We propose the application of a Time-of-Flight (ToF) satellite camera at the zenith of the pneumoperitoneum to survey the operation situs.
View Article and Find Full Text PDFMed Image Comput Comput Assist Interv
February 2014
3-D endoscopy is an evolving field of research with the intention to improve safety and efficiency of minimally invasive surgeries. Time-of-Flight (ToF) imaging allows to acquire range data in real-time and has been engineered into a 3-D endoscope in combination with an RGB sensor (640x480px) as a hybrid imaging system, recently. However, the ToF sensor suffers from a low spatial resolution (640 x 480 px) and a poor signal-to-noise ratio.
View Article and Find Full Text PDFSupervised and unsupervised vector quantization methods for classification and clustering traditionally use dissimilarities, frequently taken as Euclidean distances. In this article, we investigate the applicability of divergences instead, focusing on online learning. We deduce the mathematical fundamentals for its utilization in gradient-based online vector quantization algorithms.
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