Magnetic Shielding
Magnetic shielding for MRI systems
Active compensation systems for randomly variable magnetic fields.
Itel provides and install magnetic shielding solutions, also for high fields MRI systems, which are calculated and simulated through a specialized software solution, in order to ensure maximum magnetic confinement according to the site’s specific conditions.
For the most challenging installations, ITEL is able to solve all magnetic field interferences by means of active compensation systems.
Passive Shielding
Magnetic shielding solutions for MRI systems
Generally speaking, the magnetic shielding process consists of a partial or total installation of special steel plates on the walls of a room. While a partial installation is limited only to one wall, a complete installation provides shielding for all walls (including floor and roof).
Special attention must be paid to the choice of the material, whose physical-chemical features along with its thickness may vary according to the circumstances and depend not only on the final result sought, but also on the site’s specific environmental situation.
The design of a (partial or total) shielded room should also carefully consider the features of the MRI system and requires therefore an accurate computing analysis which could foresee the effects on the confinement of the dispersed magnetic field and most of all the field homogeneity of the MRI system, particularly where the employment of spectroscopic techniques is envisaged.
MR plant without magnetic shield
MR plant with magnetic shield
In addition, the possibility of implementing the necessary supporting structures on the installation site and the available space are also determining factors for magnetic shielding design.
To properly design magnetic shielding, Itel Telecomunicazioni uses a specialized software solution called “Vector Fields OPERA”, developed by Vector Fields, a leading company in the field of simulation software solutions for electromagnetic fields. OPERA applies the method of “finite elements” in order to solve differential equations for partial derivatives, which describe the behavior of electrical and magnetic fields. The actual model is thus split into various steps as follows:
Physical model: individuation of the specific features of the electromagnetic problem, in terms of geometry and materials, characterized by first magnetization curves, which are certified by competent bodies.
Geometric model: geometry reduction considering its active parts related to the electromagnetic problem.
Mathematical model: individuation of potential type and surrounding conditions.
Thanks to powerful work stations, it is possible to simulate and optimize magnetic shielding thickness, in order to comply with project certifications relating to dispersed magnetic induction field, while ensuring field homogeneity in the whole volume of the investigated object.
Active Shielding (Diamags FLASH®)
Active compensation systems of low frequency magnetic field variations
Diamags Flash is a patented high performance active compensation system of magnetic field fluctuations.
It shields any type of MR systems against environmental AC/DC magnetic interferences generated by subways, trains, elevators, moving metal, electrical distribution equipment causing unacceptable image quality. Due to such interferences many potential MRI sites are rejected.
Thanks to the unique active shielding performance of Diamags Flash, MRI installation is now always possible. Diamags has been used for any MR system type since 1997.
Examples of resonance without and with Diamags
Diamags Flash detects the interfering magnetic fields with a fluxgate probe and generates a counter field that eliminates the interference. Diamags Flash is composed by: main, slave, probe and correction coils. The coils, in Helmholtz configuration, can be installed either on the MRI system, hidden by the carters, or in the false ceiling/floor and in the walls.
THE DIAMAGS FLASH SYSTEM CAN ALSO BE USED FOR ELECTRON MICROSCOPY.
Design of Ionizing Radiations Shielding
The use of radiations in diagnostic imaging has allowed in the recent years to achieve excellent levels of diagnosis and prevention. The latest generation of instruments allows today a minimal exposure to ionizing radiations, which nonetheless are still a risk for operators and patients which can be minimized using appropriate protection methods and systems.
ITEL designs and installs Ionizing Radiations Shielding systems made with absorbing materials (anti-X and gamma barriers) of sufficient width to completely contain the radiation field in any point accessible to personnel and patients, within the limits of the applicable norms.