Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Western University

2009

Phantoms, Imaging

Articles 1 - 2 of 2

Full-Text Articles in Medicine and Health Sciences

The Effects Of Field-Of-View And Patient Size On Ct Numbers From Cone-Beam Computed Tomography., Katrina Y T Seet, Arvand Barghi, Slav Yartsev, Jacob Van Dyk Oct 2009

The Effects Of Field-Of-View And Patient Size On Ct Numbers From Cone-Beam Computed Tomography., Katrina Y T Seet, Arvand Barghi, Slav Yartsev, Jacob Van Dyk

Oncology Publications

Cone-beam computed tomography (CBCT) is used for patient alignment before treatment and is ideal for use in adaptive radiotherapy to account for tumor shrinkage, organ deformation and weight loss. However, CBCT images are prone to artifacts such as streaking and cupping effects, reducing image quality and CT number accuracy. Our goal was to determine the optimum combination of cone-beam imaging options to increase the accuracy of image CT numbers. Several phantoms with and without inserts of known relative electron densities were imaged using the Varian on-board imaging system. It was found that CT numbers are most influenced by the selection …


Analysis Of Carotid Lumen Surface Morphology Using Three-Dimensional Ultrasound Imaging, Bernard Chiu, Vadim Beletsky, J David Spence, Grace Parraga, Aaron Fenster Mar 2009

Analysis Of Carotid Lumen Surface Morphology Using Three-Dimensional Ultrasound Imaging, Bernard Chiu, Vadim Beletsky, J David Spence, Grace Parraga, Aaron Fenster

Medical Biophysics Publications

Carotid plaque surface irregularity and ulcerations play an important role in the risk of ischemic stroke. Ulcerated or fissured plaque, characterized by irregular surface morphology, exposes thrombogenic materials to the bloodstream, possibly leading to life- or brain-threatening thrombosis and embolization. Therefore, the quantification of plaque surface irregularity is important to identify high-risk plaques that would likely lead to vascular events. Although a number of studies have characterized plaque surface irregularity using subjective classification schemes with two or more categories, only a few have quantified surface irregularity using an objective and continuous quantity, such as Gaussian or mean curvature. In this …