One dimensional spatial resolution optimization on a hybrid low field MRI-gamma detector

Journal Article · Thu Jul 07 00:00:00 EDT 2016 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4955390· OSTI ID:22608536

Agulles-Pedrós, L., E-mail: [e-mail]; Abril, A., E-mail: [e-mail] ^[1]

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1. Medical Physics Group, Physics Department, Universidad Nacional de Colombia, Bogotá (Colombia)

Hybrid systems like Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) and MRI/gamma camera, offer advantages combining the resolution and contrast capability of MRI with the better contrast and functional information of nuclear medicine techniques. However, the radiation detectors are expensive and need an electronic set-up, which can interfere with the MRI acquisition process or viceversa. In order to improve these drawbacks, in this work it is presented the design of a low field NMR system made up of permanent magnets compatible with a gamma radiation detector based on gel dosimetry. The design is performed using the software FEMM for estimation of the magnetic field, and GEANT4 for the physical process involved in radiation detection and effect of magnetic field. The homogeneity in magnetic field is achieved with an array of NbFeB magnets in a linear configuration with a separation between the magnets, minimizing the effect of Compton back scattering compared with a no-spacing linear configuration. The final magnetic field in the homogeneous zone is ca. 100 mT. In this hybrid proposal, although the gel detector do not have spatial resolution per se, it is possible to obtain a dose profile (1D image) as a function of the position by using a collimator array. As a result, the gamma detector system described allows a complete integrated radiation detector within the low field NMR (lfNMR) system. Finally we present the better configuration for the hybrid system considering the collimator parameters such as height, thickness and distance.

• OSTI ID: 22608536
• Journal Information: AIP Conference Proceedings, Vol. 1753, Issue 1; Conference: Latin American symposium on nuclear physics and applications, Medellin (Colombia), 30 Nov - 4 Dec 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BACKSCATTERING
COLLIMATORS
COMPARATIVE EVALUATIONS
DOSIMETRY
EMISSION
GAMMA CAMERAS
GAMMA RADIATION
MAGNETIC FIELDS
NMR IMAGING
NUCLEAR MAGNETIC RESONANCE
NUCLEAR MEDICINE
ONE-DIMENSIONAL CALCULATIONS
OPTIMIZATION
PERMANENT MAGNETS
POSITRON COMPUTED TOMOGRAPHY
POSITRONS
RADIATION DETECTION
RADIATION DETECTORS
SPATIAL RESOLUTION
THICKNESS