نتایج جستجو برای: phantom ct mtf phantom autocad modulation

تعداد نتایج: 300098  

Introduction Accurate estimation of the absorbed dose in radiosensitive organs, located away from the target volume during radiotherapy, is one of the main reasons for the development of reference phantoms. The International Commission on Radiological Protection (ICRP) reference phantoms can provide a more realistic view of the human anatomy in comparison with the previously used mathematical p...

Journal: :Physics in medicine and biology 2005
J J DeMarco C H Cagnon D D Cody D M Stevens C H McCollough J O'Daniel M F McNitt-Gray

The purpose of this work was to extend the verification of Monte Carlo based methods for estimating radiation dose in computed tomography (CT) exams beyond a single CT scanner to a multidetector CT (MDCT) scanner, and from cylindrical CTDI phantom measurements to both cylindrical and physical anthropomorphic phantoms. Both cylindrical and physical anthropomorphic phantoms were scanned on an MDC...

Journal: :Japanese Journal of Radiological Technology 1990

2016
Cristina T. Dodge Eric P. Tamm Dianna D. Cody Xinming Liu Corey T. Jensen Wei Wei Vikas Kundra X. John Rong

The purpose of this study was to characterize image quality and dose performance with GE CT iterative reconstruction techniques, adaptive statistical iterative recontruction (ASiR), and model-based iterative reconstruction (MBIR), over a range of typical to low-dose intervals using the Catphan 600 and the anthropomorphic Kyoto Kagaku abdomen phantoms. The scope of the project was to quantitativ...

Journal: :Medical physics 2012
J Silkwood K Matthews P Shikhaliev

PURPOSE Photon counting spectral breast CT is feasible in part due to using an adaptive filter. An adaptive filter provides flat x-ray intensity profile and constant x-ray energy spectrum across detector surface, decreases required detector count rate, and eliminates beam hardening artifacts. However, the altered x-ray exposure profiles at the breast and detector surface may influence the distr...

2009
Barbara Blasiak Grzegorz Zwierzchowski Janusz Skowronek Patrycja Stefaniak Magdalena Dymnicka

PURPOSE 1. Comparison and verification of accuracy of the implant reconstruction method based on images from IBU and CT. 2. Estimation of influence of the implant reconstruction method on dose disposition in selected reference points. MATERIAL AND METHODS Paraffin-wax phantom with three catheters, central marker and control point were prepared. IBU unit were used for obtaining two series of i...

Journal: :Medical physics 2012
B Teimourian M R Ay M Shamsaie Zafarghandi P Ghafarian H Ghadiri H Zaidi

PURPOSE Dual-energy CT (DECT) is arguably the most accurate energy mapping technique in CT-based attenuation correction (CTAC) implemented on hybrid PET/CT systems. However, this approach is not attractive for clinical use owing to increased patient dose. The authors propose a novel energy mapping approach referred to as virtual DECT (VDECT) taking advantage of the DECT formulation but using CT...

Journal: :Investigative radiology 2005
Joachim Kettenbach Gernot Kronreif Michael Figl Martin Fürst Wolfgang Birkfellner Rudolf Hanel Wolfgang Ptacek Helmar Bergmann

PURPOSE We sought to develop a robotic system for computed tomography (CT)-guided biopsy to validate the feasibility, accuracy, and efficacy of the system using phantom tests. MATERIALS AND METHODS Ten peas (mean diameter 9.9+/-0.4 mm) embedded within a gel phantom were selected for biopsy. Once the best access was defined on CT images, the position of the phantom was recorded by an optical t...

2004
Stanislaw Szpala Marcin Wierzbicki Gerard Guiraudon Terry Peters

While most currently available minimally invasive robotically assisted cardiac surgical systems do not employ 3D image guidance, such support can be generated using pre operative images such as CT. Previously we demonstrated a virtual model of the thorax with simulated surgical instruments, and a pulsating virtual model of the coronary arteries. In this paper we report the overlay of optical en...

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