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ST 3.3 –
Protección radiológica en medicina nuclear
METHODOLOGY FOR CONSTRUCTION OF HOLLOW SPHERES USED IN
PHYSICAL PHANTOMS
Oliveira, Alex
1
*; Oliveira, Fernanda Gonçalves
2
;
Vieira, José Wilson
2
; Lima, Fernando
3
1
Centro Regional de Ciências Nucleares do Nordeste (CRCN/NE), Recife,
Universidade Federal de Brasil. Brasil.
2
Instituto Federal de Educação, Ciência e Tecnologia de Pernambuco. Brasil.
3
Centro Regional de Ciências Nucleares do Nordeste (CRCN/NE). Recife. Brasil.
* Responsible author, email: baby.oliveira@hotmail.com.br
The phantoms are usually constructed with the purpose of performing both equipment quality
control in diagnostic radiology as dosimetric evaluation of ionizing radiation. Quantitative
positron emission tomography (PET) is
generally focused on determination of accurate values
for local tracer concentration as a prerequisite for further quantification, either via standardized
uptake value (SUV) or tracer kinetic modeling. For quantitative evaluation of spatial
resolution/object size, attenuation and scatter effects is often used phantoms with hollow
spheres. Fillable, plastic-walled spheres are commercially available in several sizes.
Radioactive solutions in any concentration can be injected into the spheres. Hollow spheres
have several desirable traits, including repeatable, consistent use, and standardization across
measurements at different institutions, since identical items are distributed by a single
manufacturer. The objective of this work is to describe a methodology for construction of hollow
spheres using rapid prototyping. Rapid prototyping is a group of techniques used to quickly
fabricate a scale model of a physical part or assembly using three-dimensional (3D) computer
aided design (CAD) data. Construction of the part or assembly is usually done using 3D printing
or "additive layer manufacturing" technology. RP components are built-up gradually in layers
until the final geometry is obtained. It was used the software SolidWork (2014) to create the 3D
models of the hollow spheres. These models were based on hollow spheres of PET-CT
Phantom™ (Model PET/CT/P). There are 5 hollow spheres with inner diameter of 10 mm, 13 mm,
17 mm, 22 mm, and 28 mm. It was used the 3D printing Cubex Duo (3D Systems) to build the
hollow spheres. The material used was the ABS (acrylonitrile butadiene styrene) resin. The
models of the hollow spheres were validated by comparative analysis of PET images of the
phantom PET-CT Phantom™ with its original spheres and with the built spheres.