OPTICAL TIME DIVISION MULTIPLEXING IN MAGNETIC RESONANCE IMAGING (MRI) COILS AND TEMPERATURE MONITORING OF CRITICAL COMPONENTS INSIDE MRI COILS
Publication Date: 2014-Sep-25
The IP.com Prior Art Database
The present invention proposes an assembly wherein a single optical cable output is configured for n-number of elements in magnetic resonance (MR) coils. The assembly includes a MR coil, which has preamplifiers immediately at output of coil element. A transducer converts electrical signals to optical signals at output of preamp. Optical signals from transducer output are carried by optic fibre cables. The optic fibre cables feed the optic signals into an optical time-division multiplexing (OTDM) module. Single output channel from OTDM output carries OTDM optical signals from coil to the MRI system, where OTDM optical signals are demultiplexed for image reconstruction.
FIELD OF INVENTION
The invention generally relates to magnetic resonance imaging (MRI) coils and more particularly to optical time division multiplexing in MRI coils.
BACKGROUND OF THE INVENTION
Generally, magnetic resonance imaging (MRI) instruments transmit received MRI signals through coaxial radiofrequency (RF) cables. The cables transmit MRI signals from preamplifiers output to the side connector. However, use of conductors to carry electromagnetic signals has several disadvantages. For example, MRI system is vulnerable to noise. There is loss/ attenuation of signal along transmission path and cross talk between adjacent conductors. There is also emergence of heat spots along conducting portions of the cable due to electromagnetic (EM) induced electric currents. As a result, there exists requirement for baluns. Further, multiple conductors increases weight and complexity of coil, among others. FIG. 1 depicts a conventional MRI system with RF coil transmitting MRI signals from preamp output to the side connector.
Several conventional techniques are known for designing wireless coils. However, those techniques do not convert electrical signals to optical signals.
There are also techniques known in the art that relates to optical conversion of MR signals. For example, a conventional technique includes an MRI coil system with fiber optical connection. The MRI coil includes a local RF coil assembly. The RF coil assembly includes one or more RF coil elements. An electronic circuit is operatively connected to the RF coil elements. The electronic circuit converts electrical signals into optical signals.
Another conventional technique includes a circuit for amplifying signals received by receive coil of a magnetic resonance (MR) system. The circuit includes a preamplifier employing an active circuit device, such as a GaAs-MESFET or HEMT.
Yet another conventional technique includes an optical MRI catheter system. A catheter assembly converts electromagnetic signals received by antenna into optical signals. An optical interface assembly converts optical signals into electrical signals and electrical signals into optical signals.
One other conventional technique includes an arrangement for optical transmission of an MR signal from an MR receiving coil to a detection unit. Light of a light source is applied, by way of an optical fiber, to an electro-optical modulator which consists of an electro-optical material which is arranged between two crossed polarizers.
However, the above mentioned conventional techniques include multiple channels through the coil cable which reduces MR coil reliability.
It would be desirable to have an efficient technique to improve MR coil reliability.
BRIEF DESCRIPTION OF THE INVENTION
The present invention proposes an assembly wherein a single optical cable output is config...