1. Field of the Invention
The present invention concerns a coil for a magnetic resonance imaging system, and particularly an arrangement for fixing such a coil in place.
2. Description of the Prior Art
In a magnetic resonance system, there is a need to use a strong electromagnetic field created by high-powered radio frequency signals so as to excite nuclei in a human body to generate magnetic resonance signals, and then the magnetic resonance signals emitted from the human body are received. The said magnetic resonance signals are reconstructed into magnetic resonance images in a known manner. When a body is examined, normally it is necessary to position one or more radio frequency coils on a patient's bed with their field of view oriented at different parts of the human body, and a suitable coil needs to be placed at a corresponding position in order to carry out a scanning.
FIGS. 1 to 3 show schematic diagrams of the structure of a currently available breast coil and the manner of fixing it onto a patient bed. Tabs 14 are arranged respectively on both sides 12 of a breast coil 10 in a direction facing a patient bed 20. A plurality of slots 22 are formed respectively on both sides of the patient bed 20 along its longitudinal direction. When the breast coil 10 is used to carry out an examination, said tabs 14 are inserted along the arrow direction into the corresponding slots 22 according to the position that the patient is in said patient bed 20 or the patient's body height, so that the breast coil 10 can be fixed onto said patient bed 20.
FIGS. 4 to 6 show schematic diagrams of the structure of a currently available head coil and the manner of fixing it onto a patient bed. A number of studs 34 are arranged respectively on the bottom surface 32 of a head coil 30 in a direction facing a patient bed 20. A number of corresponding holes 24 are formed on the patient bed 20. When the head coil 30 is used to carry out an examination, the studs 34 are inserted along the arrow direction into the corresponding holes 24, so that the head coil 30 can be fixed onto the patient bed 20.
It can be seen that in such a currently available magnetic resonance imaging system, in order to fix different coils at different positions on the patient bed, it is necessary to arrange correspondingly specific structures, such as tabs and slots, studs and holes, etc., on the various coils and on the patient bed, so as to carry out the positioning or fixing therebetween.
Since specific structures have to be designed on a patient bed, such as forming slots, holes, etc., the strength of the bed base may be affected. In addition, the structures such as slots, holes, etc. tend to be soiled and collect dirt easily, therefore it is necessary for them to be cleaned regularly to prevent disease transmission.
In order to use a coil for scanning at a variety of positions, it is necessary to make a series of slots or holes on the patient bed, and this further reduces the structural strength of the patient bed. Furthermore, such a coil can only be located on the positions where the slots and holes are formed, and this leads to inconvenient placement operations, and also restricts the flexibility in using the coil.