scholarly journals Estimation of temperature-change distribution in the brain phantom by means of capacitance measurement

1999 ◽  
Vol 119 (8-9) ◽  
pp. 998-1003 ◽  
Author(s):  
Akira KIMOTO ◽  
Katsunori SHIDA
2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Tomas Pokorny ◽  
David Vrba ◽  
Jan Tesarik ◽  
Dario B. Rodrigues ◽  
Jan Vrba

This work presents the design and manufacturing of an anatomically and dielectrically realistic layered phantom of the human head that allows the insertion of ischemic and hemorrhagic stroke phantom models. A 2.5D physical phantom was designed using a representative anatomical image of the human head, which was simplified into 5 different layers that mimic the scalp, skull, cerebrospinal fluid, brain, and stroke regions in terms of anatomy and dielectric properties. Apart from the brain phantom, all other layers consist of a mixture of polyurethane rubber, graphite powder, and carbon black powder. The brain phantom is in the liquid form to facilitate the insertion of different stroke models (ischemic or hemorrhagic) with different positions and shapes. Phantoms were designed with dielectric properties valid within the frequency range 0.5–3.0 GHz, which is relevant for microwave stroke detection and classification. Molds for casting individual parts of the phantom were printed in 3D. The presented phantom is suitable for the development and testing of microwave systems and algorithms used in the detection and classification of vascular events relevant to stroke diagnosis.


2021 ◽  
Vol 94 (1119) ◽  
pp. 20200714
Author(s):  
Keith A Cauley ◽  
Patrick J Yorks ◽  
Sarah Flora ◽  
Samuel W Fielden

Objective: To investigate the effects of beam hardening by the skull on the measured radiodensity of the brain. To test a hypothesis that these effects of beam hardening are decreased using a monochromatic energy source. Methods: Selected clinical cases were reviewed in illustration. An anthropomorphic skull and brain phantom was created and scanned in a clinical CT scanner with skull, without skull, and with hemicraniectomy. The effects of beam hardening were illustrated by scanning the phantom with mono- and poly-chromatic X-ray sources. Results: In clinical cases, the HU values of the brain were consistently lower when the X-ray beam traversed the skull than when it did not. An anthropomorphic skull-and-brain phantom further demonstrated these effects, which were evident with a polychromatic energy source and absent with a virtual monochromatic energy source. Conclusions: Beam hardening by the skull lowers the measured HU values of the brain. The effects, which can impact quantitative imaging, may be mitigated by a virtual monochromatic energy source. Advances in knowledge: Beam hardening by the skull lowers the measured radiodensity of the brain. The effects may be mitigated by a virtual monochromatic energy source.


1971 ◽  
Vol 15 (2-4) ◽  
pp. 309-312 ◽  
Author(s):  
Theresa C. Henderston ◽  
R. G. Luckwill ◽  
T. Nayernouri

2011 ◽  
Vol 58 (3) ◽  
pp. 730-735 ◽  
Author(s):  
H Baghaei ◽  
Hongdi Li ◽  
Yuxuan Zhang ◽  
R A Ramirez ◽  
Shitao Liu ◽  
...  

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