نتایج جستجو برای: source ct

تعداد نتایج: 549064  

2013
J Adamson Y Yang L Rankine J Newton J Adamovics O Craciunescu M Oldham

We describe a method to directly measure the radial dose and anisotropy functions of brachytherapy sources using polyurethane based dosimeters read out with optical CT. We measured the radial dose and anisotropy functions for a Cs-137 source using a PRESAGE® dosimeter (9.5cm diameter, 9.2cm height) with a 0.35cm channel drilled for source placement. The dosimeter was immersed in water and irrad...

Journal: :Radiology 2008
James E Huprich Joel G Fletcher Jeffrey A Alexander Jeff L Fidler Sharon S Burton Cynthia H McCullough

This retrospective HIPAA-compliant study was approved by the institutional review board and institutional conflict of interest committee. Patients gave informed consent for use of medical records. The purpose of the study was to retrospectively evaluate the findings depicted at computed tomographic (CT) enterography performed with a 64-section CT system and by using neutral enteric contrast mat...

Journal: :Medical physics 2016
Simon Rit Rolf Clackdoyle Peter Keuschnigg Philipp Steininger

PURPOSE A new cone-beam CT scanner for image-guided radiotherapy (IGRT) can independently rotate the source and the detector along circular trajectories. Existing reconstruction algorithms are not suitable for this scanning geometry. The authors propose and evaluate a three-dimensional (3D) filtered-backprojection reconstruction for this situation. METHODS The source and the detector trajecto...

Journal: :Advances in clinical and experimental medicine : official organ Wroclaw Medical University 2012
Tomasz Kraśnicki Przemysław Podgórski Maciej Guziński Anna Czarnecka Krzysztof Tupikowski Jerzy Garcarek Marek Marek Sąsiadek

Dual energy CT (DECT) was conceived at the very beginning of the computed tomography era. However the first DECT scanner was developed in 2006. Nowadays there are three different types of DECT available: dual-source CT with 80(100) kVp and 140 kVp tubes (Siemens Medical Solution); dual-layer multi-detector scanner with acquisition 120 or 140kVp (Philips Healthcare); CT unit with one rapid kVp s...

2013
K. Achterhold M. Bech S. Schleede G. Potdevin R. Ruth R. Loewen F. Pfeiffer

A laser-driven electron-storage ring can produce nearly monochromatic, tunable X-rays in the keV energy regime by inverse Compton scattering. The small footprint, relative low cost and excellent beam quality provide the prospect for valuable preclinical use in radiography and tomography. The monochromaticity of the beam prevents beam hardening effects that are a serious problem in quantitative ...

Journal: :Retina 2015
Jorge Ruiz-Medrano Ignacio Flores-Moreno Pablo Peña-García Javier A Montero Jay S Duker José M Ruiz-Moreno

PURPOSE To determine the difference in macular choroidal thickness (CT) profile between eyes in healthy individuals using swept-source optical coherence tomography. DESIGN Cross-sectional noninterventional study. PARTICIPANTS One hundred and forty eyes from 70 healthy patients with spherical equivalent between ± 3 D and with difference ≤ 0.25 D between eyes were scanned using a swept-source...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2008
Matthias Hofmann Florian Steinke Verena Scheel Guillaume Charpiat Jason Farquhar Philip Aschoff Michael Brady Bernhard Schölkopf Bernd J Pichler

UNLABELLED For quantitative PET information, correction of tissue photon attenuation is mandatory. Generally in conventional PET, the attenuation map is obtained from a transmission scan, which uses a rotating radionuclide source, or from the CT scan in a combined PET/CT scanner. In the case of PET/MRI scanners currently under development, insufficient space for the rotating source exists; the ...

2015
Amir M. Owrangi Shruti Jolly James M. Balter Yue Cao Katherine E. Maturen Lisa Young Tong Zhu Joann I. Prisciandaro

We present an institutional experience on the clinical implementation of magnetic resonance (MR)-guided vaginal brachytherapy using commercially available solid applicator models. To test the fidelity of solid applicator models to digitize vaginal cylinder applicators, three datasets were evaluated. The first included 15 patients who were simulated with CT alone. Next, a water phantom was used ...

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