نتایج جستجو برای: hybrid phantoms

تعداد نتایج: 202911  

Journal: : 2022

Our team has developed a number of phantoms suitable for advanced training ultrasound diagnostic doctors, as well testing their knowledge and skills. Phantoms are made durable materials can be considered analogues foreign commercial models. The used allow modeling different levels echogenicity, rigidity, they given clinically realistic shapes. applicable practicing the skills diagnostics in gra...

Journal: :iranian journal of radiation research 0
n. demir physics department, faculty of arts and sciences, uludag university, gorukle campus,16059, bursa, turkey u. akar tarim physics department, faculty of arts and sciences, uludag university, gorukle campus,16059, bursa, turkey o. gurler physics department, faculty of arts and sciences, uludag university, gorukle campus,16059, bursa, turkey

background: in radiation therapy, water is the phantom material of choice, both for reference and for relative dosimetry measurements. solid phantoms, however, are more useful for routine measurements because they tend to be more robust and easier to set up than water phantoms. materials and methods: fluka input data cards have been arranged in sequential order. a simple cylindrical geometry wi...

Journal: :iranian journal of radiation research 0
t. allahverdi pourfallah department of medical physics and biomedical engineering, tehran university of medical sciences, tehran, iran m. allahverdi department of medical physics and biomedical engineering, tehran university of medical sciences, tehran, iran n. riyahi alam department of medical physics and biomedical engineering, tehran university of medical sciences, tehran, iran m.r. ay research center for science and technology in medicine, tehran university of medical sciences, tehran, iran m.h. zahmatkesh novin medical radiation institute, tehran, iran

background: polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. mri polymer gel dosimeters are tissue equivalent and can act as a phantom material. in this study the obtained isodose maps with pagat polymer gel dosimeter were compared to those calculated with egsnrs for singleshot irradiations of 8 and 18 mm collimators of gamma ...

Journal: :journal of dentistry, tehran university of medical sciences 0
masoud varshowsaz sepideh goorang sara ehsani zeynab azizi sepideh rahimian

objectives: bone quality and quantity assessment is one of the most important steps in implant treatment planning. different methods such as computed tomography (ct) and recently suggested cone beam computed tomography (cbct) with lower radiation dose and less time and cost are used for bone density assessment. this in vitro study aimed to compare the tissue density values in hounsfield units (...

Journal: :Magnetic resonance in medicine 2011
Amir Moussavi-Biugui Bram Stieltjes Klaus Fritzsche Wolfhard Semmler Frederik B Laun

For the validation of complex diffusion imaging techniques like q-ball imaging that aim to resolve multiple fiber directions, appropriate phantoms are highly desirable. However, previous q-ball imaging phantoms had diffusion anisotropies well below those of in vivo white matter. In this work, fiber phantoms of well-defined geometry are presented. The fibers are wound on a spherical spindle yiel...

2016
Anna Kelaranta

Organ dose is the absorbed radiation energy from ionizing radiation to an organ, divided by the organ mass. Organ doses of a patient cannot be measured directly in the patient, but their determination requires dose measurements in anthropomorphic patient models i.e. phantoms or Monte Carlo simulations. Monte Carlo simulations can be performed for example by using computational phantoms or patie...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2012
Thomas S C Ng James R Bading Ryan Park Hargun Sohi Daniel Procissi David Colcher Peter S Conti Simon R Cherry Andrew A Raubitschek Russell E Jacobs

UNLABELLED Noninvasive methods are needed to explore the heterogeneous tumor microenvironment and its modulation by therapy. Hybrid PET/MRI systems are being developed for small-animal and clinical use. The advantage of these integrated systems depends on their ability to provide MR images that are spatially coincident with simultaneously acquired PET images, allowing combined functional MRI an...

ژورنال: سنجش و ایمنی پرتو 2020

This study evaluated the impact of contrast material on the estimation of absorbed dose due to computed tomography pulmonary angiography (CTPA) using the ICRP reference phantoms. To address this issue, we modified the previously developed physiologically based pharmacokinetic (PBPK) model to be conformed to the ICRP reference phantoms. Regarding the standard contrast material injection protocol...

Journal: :journal of lasers in medical sciences 0
mohsen erfanzadeh laser and plasma research institute, shahid beheshti university.g.c., tehran, iran. saied alikhani laser and plasma research institute, shahid beheshti university.g.c., tehran, iran. mohammad ali ansari laser and plasma research institute, shahid beheshti university.g.c., tehran, iran. ezeddin mohajerani laser and plasma research institute, shahid beheshti university.g.c., tehran, iran.

introduction: in this study, arrangement of a low-cost optical tomography device compared to other methods such as frequency domain diffuse tomography or time domain diffuse tomography is reported. this low-cost diffuse optical imaging technique is based on the detection of light after propagation in tissue. these detected signals are applied to predict the location of in-homogeneities inside p...

Ali Soleymani Meigooni Reza Faghihi, Sedigheh Sina

Introduction After the publication of Task Group number 43 dose calculation formalism by the American Association of Physicists in Medicine (AAPM), this method has been known as the most common dose calculation method in brachytherapy treatment planning. In this formalism, the water phantom is introduced as the reference dosimetry phantom, while the attenuation coefficient of the sources in the...

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