CN202330682U

CN202330682U - Miniature animal coil in magnetic resonance system

Info

Publication number: CN202330682U
Application number: CN2011204829222U
Authority: CN
Inventors: 刘佩琴; 杨昌陈
Original assignee: SUZHOU MEDCOIL HEALTHCARE CO Ltd
Current assignee: SUZHOU MEDCOIL HEALTHCARE CO Ltd
Priority date: 2011-11-29
Filing date: 2011-11-29
Publication date: 2012-07-11
Anticipated expiration: 2021-11-29

Abstract

The utility model discloses a miniature animal coil of a magnetic resonance system. The miniature animal coil comprises a plurality of antenna units and is characterized in that the number of the antenna units is more than two, the adjacent antenna units of the coil are partially coincided, and a capacitor or inductor decoupling device is arranged between two antenna units at diagonal corners. The miniature animal coil is better in decoupling effect between coil units, higher in sensitivity (signal-to-noise ratio), more flexible in PAT (parallel acquisition technique) selection and better in PAT effect.

Description

Meiofauna coil in a kind of magnetic resonance system

Technical field

the utility model belongs to the magnetic resonance imaging field, is specifically related to the meiofauna coil in a kind of magnetic resonance system.

Background technology

magnetic resonance system is a kind of high-end medical imaging devices, and wherein RF receiving coil is very important parts of magnetic resonance system.RF receiving coil effect therein can be likened adult's eyes, and the final sharpness of image directly is directly proportional with its signal to noise ratio (S/N ratio) (sensitivity).For the sharpness that improves image (or signal to noise ratio (S/N ratio), or sensitivity), the First Principles of general coil design is under the situation of the size that satisfies scanning position or object, with the size of coil do try one's best scanning position or object.Such as the design of a head coil, the head that its size is at first wanted to satisfy most patients (such as the patient's ratio more than 95%) can both be put into coil, but the size of head coil again can not be excessive.Because if coil dimension is too little, having a lot of patients can't use, and coil dimension is too big, can reduce the sharpness of MRI again.RF receiving coil can be according to the name nominating of scanning position or object, and is varied.In scanning human body different parts, generally need with special-purpose coil, such as the coil of scanning head be called head coil, the kneed coil of scanning is called the knee joint coil, also has heart coil, spine coil or the like.Except to the human body, some coil also specialized designs is used for to some animal imaging, and these coils can be called animal coil.Be that the biomedical research of object can be avoided the risk that on the person, experimentizes and brought with the animal, and can strict control zoopery condition, reduce the influence of individual difference.Iconography means, especially magnetic resonance imaging are one of instruments indispensable in the present Research of Animal Model for Study.With respect to larger animal, toy has cheaper, breed and the management more easily of cost, the advantage of when magnetic resonance imaging, also placing more easily.So in present magnetic resonance animal imaging, the application of meiofauna just becomes more and more widely, and has occupied very high ratio.In a word, the magnetic resonance radio-frequency coil of meiofauna has extensive market prospects.In order to obtain the preferable image quality, animal coil, the especially design of meiofauna coil at first are to adopt less relatively coil dimension, can under the situation that satisfies most of meiofauna application, improve the signal to noise ratio (S/N ratio) of image as much as possible like this.Except selecting undersized coil, the parallel acquisition technique in the magnetic resonance imaging (Parallel acquisition Technique is called for short PAT) also can effectively improve picture quality.Such as reducing image artifacts, accelerate image imaging speed.PAT is extremely important a, otherwise effective technique in the present magnetic resonance imaging in a word.But the imaging effect of PAT (or ability) is except following the magnetic resonance parameters in series (like FOV; Over-sampling etc.) beyond setting, the selection of aspect, phase-encoding direction (phase encodeing direction) are relevant; Also very big relation is arranged, so the design arranged evenly of the coil unit of meiofauna coil is a key of animal imaging effect with the design of coil, the quantity and the positional alignment of coil unit.On the magnetic resonance market, the antenna element of meiofauna coil distributes generally has 2 kinds, as depicted in figs. 1 and 2 at present, and it is classical Birdcage (birdcage coil) that coil unit shown in Figure 1 distributes, and the antenna load point of 2 omnidirectional distribution (becoming 90 ° of distributions) is arranged.This coil is in the past because homogeneity is high, has 41% signal to noise ratio (S/N ratio) to improve than the coil of individual antenna unit, once is widely used.But in today that phased-array coil is used widely, again because signal to noise ratio (S/N ratio) is relatively poor relatively, parallel imaging performance relative mistake etc. are former thereby backward.Now the maximum of usefulness are phased-array coils.Coil shown in Figure 2 has 4 independently antenna elements, becomes the distribution of 1*4 in annular direction, and it is a phased-array coil.It has, and processing and fabricating is easy, signal to noise ratio (S/N ratio) is higher relatively, parallel imaging also compares flexible characteristic.But its defective is to have only the good effect of decoupling can be arranged between the adjacent antenna element, and between 2 pairs of antenna elements of relative position, makes that coupling is relatively large because can't adopt the measure of decoupling, and has reduced the signal to noise ratio (S/N ratio) of whole winding.Because its 4 antenna elements are arranged all in annular direction, make its parallel imaging direction corresponding speedup factor to be arranged so in addition in annular direction.

The utility model content

the utility model purpose is: provide a kind of have the effect of decoupling between the better coil unit, higher sensitivity (signal to noise ratio (S/N ratio)), more flexibly PAT select and the magnetic resonance system of better PAT effect in the meiofauna coil.

The technical scheme of the utility model is: the meiofauna coil in a kind of magnetic resonance system, comprise a plurality of antenna elements, and it is characterized in that the antenna element of said coil is greater than two, said adjacent antenna element partially overlaps.

are further, and said antenna element is 4, and said 4 antenna elements become the mode of 2*2 to arrange, and are divided into 2 sections on vertically, and every section has 2 antenna elements on annular direction.

are further, and electric capacity or inductance isolator are arranged between said clinodiagonal antenna element.

are further, and said antenna element is 8 limit shapes.

the utility model has the advantages that: have the effect of decoupling between the better coil unit, higher sensitivity (signal to noise ratio (S/N ratio)), more flexible PAT selection and better PAT effect.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

Fig. 1 is the antenna unit structure figure of existing meiofauna coil.

Fig. 2 is the antenna unit structure figure of another kind of existing meiofauna coil.

Fig. 3 is the antenna unit structure figure of the meiofauna coil of the utility model.

The signal to noise ratio (S/N ratio) of coil of the existing 1*4 of Fig. 4 and the 2*2 coil of the utility model compares, and left image is 1*4, and the right is the coil of 2*2.

The signal noise ratio (snr) of image of the 2*2 coil of the existing 1*4 coil of Fig. 5 and the utility model is (data are picked up from water mould axis) relatively.

Embodiment

embodiment: the meiofauna coil in the kind magnetic resonance system as shown in Figure 3, have 4 independently antenna elements, become the arrangement mode of 2*2, it is divided into 2 sections in the vertical, and every section has 2 antenna elements on annular direction.4 of present embodiments independently antenna element be shaped as octagon, the antenna element of other shapes can reach the effect of the utility model equally.Do the analysis of a uncoupling down in the face of 4 unit of this coil: 1. can adopt the method uncoupling of Overlap (partially overlapping) between any two adjacent cells.Between these 4 unit except adjacent relation is arranged, also having two groups of unit in addition is clinodiagonal relations, because these hypotenuses can adopt the mode of capacitor decoupling to handle at a distance of very near, can reach very desirable uncoupling effect.Comprehensive above 2 point analysiss can be found, between any 2 of these 4 unit, can both take good uncoupling measure.Experiment shows that also the design of this coil has obtained good uncoupling effect, has improved the signal to noise ratio (S/N ratio) of whole winding.In addition because the arrangement of 4 antenna elements of this coil except on the annular direction, still has the arrangement of factor 2 in the vertical.So from the selection of parallel imaging, have more flexibly and select, experiment proves that also the design of its relative Fig. 2 of parallel imaging effect is significantly improved.The signal to noise ratio (S/N ratio) comparative result that has shown this coil and coil shown in Figure 2 like Fig. 4, experimental result shown in Figure 5; Wherein these 2 internal coil diameter sizes are identical; The antenna element of the 2*2 of the utility model distributes not only can carry out parallel imaging on annular direction, also can on y direction, carry out parallel imaging.Parallel imaging is selected more flexible, and effect is more superior.This structure can guarantee can both adopt good method and decouple between any 2 of 4 independent antenna elements, and uncoupling is more thorough, has improved signal to noise ratio (S/N ratio) effectively.Image as shown in Figure 5, ordinate SNR are ratios, dimensionless.Horizontal ordinate is the distribution of pixel, and actual picture is the 256*256 pixel, has only taken out most representative water mould axis among Fig. 4 among Fig. 5, and this line is made up of 256 points.Can find out that from above two pictures the relative 1*4 distribution coil of 2*2 distribution coil has tangible signal to noise ratio (S/N ratio) advantage, image is also more even.

above embodiment is merely the utility model a kind of embodiment wherein, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the utility model claim.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the utility model design, can also make some distortion and improvement, these all belong to the protection domain of the utility model.Therefore, the protection domain of the utility model patent should be as the criterion with accompanying claims.

Claims

1. the meiofauna coil in the magnetic resonance system comprises a plurality of antenna elements, it is characterized in that said antenna element is greater than two, and the adjacent antenna element of said coil partially overlaps.

2. the meiofauna coil in the magnetic resonance system according to claim 1 is characterized in that, said antenna element is 4, and said 4 antenna elements become the mode of 2*2 to arrange, and is divided into 2 sections on vertically, and every section has 2 antenna elements on annular direction.

3. the meiofauna coil in the magnetic resonance system according to claim 2 is characterized in that, electric capacity or inductance isolator are arranged between said clinodiagonal antenna element.

4. according to the meiofauna coil in claim 2 or the 3 described magnetic resonance systems, it is characterized in that said antenna element is 8 limit shapes.