Results 141 to 150 of about 1,779,765 (198)

A phantom for testing Cone Beam CTs

Physical and Engineering Sciences in Medicine, 2020
Cone Beam Computed Tomography (CBCT) scanners are becoming more common for dental and maxillofacial/head scanning, but performing image quality tests on these systems is difficult. There are quality assurance (QA) phantoms commercially available but they can be expensive, bulky and not optimised for CBCT imaging limits.
Steven Muir, Johnny Laban
openaire   +2 more sources

Dental cone beam CT: A review

Physica Medica, 2015
For the maxillofacial region, there are various indications that cannot be interpreted from 2D images and will benefit from multiplanar viewing. Dental cone beam CT (CBCT) utilises a cone- or pyramid-shaped X-ray beam using mostly flat-panel detectors for 3D image reconstruction with high spatial resolution. The vast increase in availability and amount
Timo, Kiljunen   +3 more
openaire   +2 more sources

Crescent artifacts in cone‐beam CT

Medical Physics, 2011
Purpose:In image‐guided radiation therapy, cone‐beam CT has been adopted for three‐dimensional target localization in the treatment room. In many of these cone‐beam CT images, dark and light crescent artifacts can be seen. This study investigates potential causes of this artifact and a technique for mitigating the crescents.Methods:Three deviations ...
William, Giles   +3 more
openaire   +2 more sources

Cone-beam reconstruction for Micro-CT

Proceedings IEEE International Symposium on Biomedical Imaging, 2003
X-ray micro-CT has been a focus in the CT/Micro-CT Lab, the University of Iowa. In this paper, some recent progress we made on cone-beam micro-CT is described. First, we address approximation reconstruction using Feldkamp-type algorithms with multiple X-ray sources and displaced detector configurations.
Ge Wang 0001   +4 more
openaire   +2 more sources

Towards cone-beam CT thermometry

SPIE Proceedings, 2013
Temperature monitoring and therefore the final treatment zone achieved during a cone-beam CT (CBCT) guided ablation can prevent overtreatment and undertreatment. A novel method is proposed to detect changes in consecutive CBCT images obtained from projection reconstructions during an ablation procedure.
Ming Li 0052   +8 more
openaire   +1 more source

Cone-beam CT for radiotherapy applications

Physics in Medicine and Biology, 1995
Clinical implementation of cone-beam tomography has been hampered by the lack of two-dimensional electronic x-ray detectors that can encompass the full width of the body. We encountered the undersized detector problem in our development of a cone-beam CT system for radiotherapy applications.
P S, Cho, R H, Johnson, T W, Griffin
openaire   +2 more sources

Auto calibration of a cone‐beam‐CT

Medical Physics, 2012
Purpose:This paper introduces a novel autocalibration method for cone‐beam‐CTs (CBCT) or flat‐panel CTs, assuming a perfect rotation. The method is based on ellipse‐fitting. Autocalibration refers to accurate recovery of the geometric alignment of a CBCT device from projection images alone, without any manual measurements.Methods:The authors use test ...
Daniel, Gross   +4 more
openaire   +2 more sources

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