نتایج جستجو برای: ccd based optical ct image reconstruction

تعداد نتایج: 3529095  

Ali Shabestani Monfared, Gholam Reza Ataei Mohammad Davoudi Sara Delfan Shiva Shoubkolaei

Introduction: Since demand for computed tomography (CT) examinations is growing, patients are exposed more frequently to ionizing radiation. To reduce the dose delivered to patients in each scan, CT technologists can change the image acquisition parameters. However, this reduces image quality. Present study aimed to optimize and reduce radiation dose in a CT of the paranasal si...

2004
Christian Wöhler

In this paper image-based techniques for 3D surface reconstruction are presented which are especially suitable for (but not limited to) coplanar light sources. The first approach is based on a single-image shape from shading scheme, combined with the evaluation of at least two further images of the scene that display shadow areas. The second approach allows the reconstruction of surfaces by an ...

2014
Emil Y. Sidky Rick Chartrand John M. Boone Xiaochuan Pan

Exploiting sparsity in the image gradient magnitude has proved to be an effective means for reducing the sampling rate in the projection view angle in computed tomography (CT). Most of the image reconstruction algorithms, developed for this purpose, solve a nonsmooth convex optimization problem involving the image total variation (TV). The TV seminorm is the `1 norm of the image gradient magnit...

Journal: :Current Radiology Reports 2013

Chegeni Nahid Elahe Soroosh Fard Marziyeh Tahmasbi Mohammad Javad Tahmasebi Birgani

Introduction: The quality of CT images used for treatment planning of cancer patients is an important issue in accurate outlining of the tumor volume and organs at risk. Different kernels in CT scanner systems are available for improving the image quality. Applying these kernels  on   CT  images  will  change   the   CT  numbers  and  electron   density   of   tissues, conse...

Journal: :archives of cardiovascular imaging 0
bernhard bischoff institute for clinical radiology, ludwig-maximilians-university hospital munich, 80337 munchen, germany; dzhk (german centre for cardiovascular research), partner site munich heart alliance, munich, germany; institute for clinical radiology, ludwig-maximilians-university hospital munich, 80337 munchen, germany. tel: +49-89440044858 lucas l geyer institute for clinical radiology, ludwig-maximilians-university hospital munich, 80337 munchen, germany; dzhk (german centre for cardiovascular research), partner site munich heart alliance, munich, germany maximilian f reiser institute for clinical radiology, ludwig-maximilians-university hospital munich, 80337 munchen, germany; dzhk (german centre for cardiovascular research), partner site munich heart alliance, munich, germany ullrich g mueller lisse institute for clinical radiology, ludwig-maximilians-university hospital munich, 80337 munchen, germany; dzhk (german centre for cardiovascular research), partner site munich heart alliance, munich, germany

background motion artifacts that degrade image quality of coronary ct angiography (ccta) in patients with high heart rates may be reduced with specific automatic motion correction algorithms (amc). conclusions ccta image quality improves significantly with amc in patients with high heart rates and reduces the proportion of non-diagnostic examinations. results mean heart rate during ccta was 61 ...

Journal: :Medical image computing and computer-assisted intervention : MICCAI ... International Conference on Medical Image Computing and Computer-Assisted Intervention 2012
Yu Zhang Guorong Wu Pew-Thian Yap Qianjin Feng Jun Lian Wufan Chen Dinggang Shen

Image resolution in 4D-CT is a crucial bottleneck that needs to be overcome for improved dose planning in radiotherapy for lung cancer. In this paper, we propose a novel patch-based algorithm to enhance the image quality of 4D-CT data. Our premise is that anatomical information missing in one phase can be recovered from complementary information embedded in other phases. We employ a patch-based...

2007
George Eliopoulos Milos Island Costas Stefanis Christer Halldin

While the Anger gamma camera was dominant for several decades for nuclear medicine imaging, there are a number of significant developments in progress. The large increase of the usage of PET scanners has been a result of new detector materials such as LSO, GSO, YAP etc, improved electronics and algorithms such as list mode reconstruction and in particular the combination with CT. Finally althou...

Journal: :AJR. American journal of roentgenology 2009
Amy K Hara Robert G Paden Alvin C Silva Jennifer L Kujak Holly J Lawder William Pavlicek

OBJECTIVE The purpose of this study was to evaluate the image noise, low-contrast resolution, image quality, and spatial resolution of adaptive statistical iterative reconstruction in low-dose body CT. MATERIALS AND METHODS Adaptive statistical iterative reconstruction was used to scan the American College of Radiology phantom at the American College of Radiology reference value and at one-ha...

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