نتایج جستجو برای: anthropomorphic phantom

تعداد نتایج: 19149  

2003
Frédéric J. P. Richard Predrag R. Bakic Andrew D. A. Maidment

The amount of breast compression applied during a mammographic exam affects the appearance of mammograms by introducing variations in the shape, position, and contrast of breast anatomical structures, which can conceal existing breast abnormalities or generate false alarms. Due to the complex tissue organization and elastic properties of the breast and the projective nature of mammography, rigi...

2010
Vagner Ferreira Cassola Gabriela Hoff

OBJECTIVE: To compare data regarding dosimetry and photons fluence in different breast phantoms, discussing constancy tests and dosimetry applied to mammography. MATERIALS AND METHODS: Different homogeneous breast phantoms and one anthropomorphic voxel phantom were developed for collection of data regarding total absorbed dose in the phantom, absorbed dose in the glandular tissue material-equiv...

2011
J. M. Warwick S. Rubow M. du Toit E. Beetge P. Carey P. Dupont

Purpose. Striatal single photon emission computed tomography (SPECT) imaging of the dopaminergic system is becoming increasingly used for clinical and research studies. The question about the value of nonuniform attenuation correction has become more relevant with the increasing availability of hybrid SPECT-CT scanners. In this study, the value of nonuniform attenuation correction and correctio...

Journal: :Medical physics 2002
M Partridge M Ebert B M Hesse

A method of reconstructing three-dimensional, in vivo dose distributions delivered by intensity-modulated radiotherapy (IMRT) is presented. A proof-of-principle experiment is described where an inverse-planned IMRT treatment is delivered to an anthropomorphic phantom. The exact position of the phantom at the time of treatment is measured by acquiring megavoltage CT data with the treatment beam ...

Journal: :Journal of Biomedical Optics 2021

Significance: Recovering accurate oxygenation estimations in the breast with quantitative photoacoustic tomography (QPAT) is not straightforward. Accurate light fluence models are required, but unknown ground truth of makes it difficult to validate them. Phantoms often used for validation, most reported phantoms have a simple architecture. Fluence developed these simplistic objects application ...

Introduction: Phantom studies facilitate the implementation of radiation dose surveillance as a function of radiographic technical parameters for minimizing patient radiation dose. The evidence of such investigations can then be used to evaluate technical parameters used in the radiographic procedures to reduce radiation dose without compromising the image quality. Material and Methods: This ex...

Journal: :Physics and Imaging in Radiation Oncology 2023

Background/PurposeThis study determines and compares the geometric setup errors between stereoscopic x-ray kilo-voltage cone beam CT (CBCT) in phantom tests on a linear accelerator (linac) for image-guided (IG) stereotactic radiotherapy of intracranial tumors. Additionally, dose-volume metrics target volumes CBCT were evaluated.Materials/MethodsA Winston-Lutz- an anthropomorphic used. The mean ...

Journal: :Radiology 2006
Tracy A Jaffe Rendon C Nelson G Allan Johnson Ellie R Lee Terry T Yoshizumi Carolyn R Lowry Anthony B Bullard David M DeLong Erik K Paulson

Institutional review board approval and waiver of consent were obtained for the patient component of this retrospective HIPAA-compliant study. By using an anthropomorphic phantom and metal oxide semiconductor field effect transistor detectors, radiation dose was determined for one eight-detector row and two 16-detector row computed tomographic (CT) protocols. A custom phantom was scanned by usi...

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