CN102305917A

CN102305917A - Horizontal field head coil used for magnetic resonance imaging system

Info

Publication number: CN102305917A
Application number: CN201110217444A
Authority: CN
Inventors: 罗伟平
Original assignee: SUZHOU MEDCOIL HEALTHCARE CO Ltd
Current assignee: SUZHOU MEDCOIL HEALTHCARE CO Ltd
Priority date: 2011-08-01
Filing date: 2011-08-01
Publication date: 2012-01-04
Also published as: WO2013017043A1

Abstract

The invention discloses a horizontal field head coil used for a magnetic resonance imaging system. The horizontal field head coil comprises eight annular units which are divided into an upper part and a lower part, both the upper part and the lower part have four units in a 2*2 arrangement, and part circuits of the four units of the upper part are placed in the lower part. The horizontal field head coil used for a magnetic resonance imaging system has the characteristics of simple structure, a high signal to noise ratio, and good patient visual field.

Description

A kind of level field head coil that is used for magnetic resonance imaging system

Technical field

the invention belongs to the magnetic resonance imaging field, are specifically related to a kind of level field head coil that is used for magnetic resonance imaging system.

Background technology

magnetic resonance imaging system can be divided into horizontal magnetic resonance system and perpendicualr field magnetic resonance system according to the magnetic direction of main magnet.The level field system refers to the magnetic direction of magnet and follows people's trunk parallel, points to step or opposite from brain.The magnetic direction that the perpendicualr field system refers to magnet is vertical with people's trunk direction, points to the back side such as the front from the people.The magnetic direction of magnet is the most important reference frame of design radio-frequency coil, and is vertical with the magnet direction as much as possible because the antenna element in the coil needs, and could obtain best radio-frequency drive or receiving function.On the performance of radio-frequency coil, sensitivity (or more popular saying signal to noise ratio (S/N ratio)) and homogeneity are two most important measurement indexs.From doctor's operation convenience and patient comfort, two parts unlatching was a very important function about the radio-frequency maser coil had, because patient's head can be placed in the coil very easily like this.In order to reduce part patient's claustrophobia, head coil should have the open as far as possible visual field in addition.Last this experiment often need be carried out visual stimulus to tested object because head coil can be used for doing the research experiment of neuro-cognitive, and at this moment having the open visual field also is an essential condition to head coil.On the magnetic resonance market, the commercial radio-frequency maser coil of two classics is arranged at present.A is Siemens's 12 channel head coils, and another money is the 8 channel head coils that Invivo company produces.Siemens 12 passage coils adopt is 2 * 6 antenna element layout, as shown in Figure 1; Invovo 8 channel line coil unit layouts are as shown in Figure 2.12 passage coils of Siemens are divided into fully independently two parts up and down, and ch1-ch6 is the first half, and ch7-ch12 belongs to the latter half.The first half can therefrom be removed, again the first half covered after on patient lies, and be patient's the visual field in the dashed region among Fig. 1.Like this be designed with defective; Be exactly among wherein 4 the passage ch7, ch9, ch10, ch12 of wherein 4 passage ch1, ch3, ch4, ch6 and the latter halfs of the first half; There are 4 groups of adjacent unit group ch1/ ch7, ch3/ ch9, ch4/ ch10, ch6/ ch12 can't take the measure of decoupling; Can cause the signal to noise ratio (S/N ratio) of these 8 passages to receive bigger influence like this, and finally influence the signal to noise ratio (S/N ratio) of whole winding.The 8 passage coils of Invivo do not have the first half separated structures, are patient's the visual field in the dashed region.Though such design can not influence the signal to noise ratio (S/N ratio) of coil because do not have last the latter half separation function, patient lie into or leave relatively inconvenience of coil, excessive because of intermediate transverse girder in addition, also some effects patient's the visual field.

Summary of the invention

the present invention seeks to: the level field head coil that is used for magnetic resonance imaging system that a kind of patient visual field is good, signal to noise ratio (S/N ratio) is high is provided.

Technical scheme of the present invention is:

a kind of level field head coil that is used for magnetic resonance imaging system is characterized in that, comprises 8 annular elements, is divided into two parts up and down, and the first half and the latter half respectively have 4 unit that are 2 * 2 arrangements; 4 unit of the first half respectively have partial circuit to be placed on the latter half.

are further, between any two adjacent cells of said the first half, adopt the structure of common edge.

are further, and the intersection of 4 unit of said the first half adopts 4 electric capacity bridge architectures.

are further, and said the first half and the latter half surround two and open the tubular coil that tubular coil or open, the other end is drawn in or sealed.

Advantage of the present invention is:

1. go up 8 antenna element signals of the latter half and all can export together from the latter half, convenient to greatest extent 8 road signals are exported together;

2. can adopt up and down and to open, make things convenient for patient lie into;

3. in 4 of the first half unit, can have well between any two unit and decouple, obviously optimize signal to noise ratio (S/N ratio);

have 4. been reduced the area of patient's disturbance of disturbance of visual field to greatest extent, have optimized patient's field range.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is further described:

Fig. 1 is the antenna element layout of Siemens's 12 passage coils.

Fig. 2 is the antenna element layout of Invovo 8 passage coils.

Fig. 3 is the antenna element layout of 8 passage coils of the present invention.

Fig. 4 is the stereographic map of a kind of embodiment of 8 passage coils of the present invention.

Fig. 5 is the stereographic map of a kind of embodiment of 8 passage coils of the present invention.

Fig. 6 is that the image SNR of 8 channel head coils of the present invention and 12 channel head coils compares.

Embodiment

embodiment: the level field head coil that is used for magnetic resonance imaging system as shown in Figure 3 comprises not exclusively independently two parts up and down; Wherein the first half be clipped in about part in two dotted lines, comprise unit ch1, ch4, ch5, ch8; The latter half comprises unit ch2, ch3, ch6, ch7; 4 unit ch1 of the first half, ch4, ch5, ch8 have a limit in the latter half.The first half can therefrom be removed, and the first half is covered after on patient lies again.Between the first half unit ch1, ch4, ch5, any two adjacent cells of ch8, adopt the structure of common edge: there is electric capacity c9 on the shared limit of unit ch4 and ch8 on the limit; There is electric capacity c10 on the shared limit of unit ch8 and ch5 on the limit; There is electric capacity c11 on the shared limit of unit ch5 and ch1 on the limit; There is electric capacity c12 on the shared limit of unit ch1 and ch4 on the limit.The intersection of 4 unit of the first half adopts 4 electric capacity bridge architectures: electric capacity c3, c4, c5 and c6 have constituted the electric capacity bridge architecture.The level field head coil that is used for magnetic resonance imaging system of the present invention can expand to the level field coil of a cylindrical shape or annular tubular such as oval cylinder or square tubular, as Fig. 4, two shown in Figure 5 open that tubular coil or one open, to draw the tubular coil in be two embodiment of the present invention in the other end.According to said structure; Made the 1.5T level field head coil of 8 passages, test result is as shown in Figure 6, and wherein block curve is from 8 passage coils of present embodiment; Dotted line come Siemens certain just production and sales from 12 passage coils, this two statures internal coil diameter size is identical.Ordinate SNR is a ratio, dimensionless.Horizontal ordinate is the distribution of pixel, and actual picture is the 256*256 pixel, has only taken out most representative medium line among Fig. 6, and this line is made up of 256 points.Can find out that from above two pictures the relative 12 passage coils of 8 passage coils have tangible signal to noise ratio (S/N ratio) advantage, image is also more even.Test result shows that this coil performance is good, and signal to noise ratio (S/N ratio), the equal function admirable of homogeneity can be opened up and down, and the patient visual field is good, and 8 road signals are all from the latter half output, and the system of being convenient to connects.The present invention and existing level field head coil contrast as follows:

Coil producer	Signal to noise ratio (S/N ratio)	The image homogeneity	Whether can open	Whether the visual field is good
					Siemens	Not ideal enough	Desirable	Be	Well
Invivo	Desirable	Not ideal enough	Not	Well
					This patent	Desirable	Desirable	Be	Well

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

Claims

1. a level field head coil that is used for magnetic resonance imaging system is characterized in that, comprises 8 annular elements, is divided into two parts up and down, and the first half and the latter half respectively have 4 unit that are 2 * 2 arrangements; 4 unit of the first half respectively have partial circuit to be placed on the latter half.

2. the level field head coil that is used for magnetic resonance imaging system according to claim 1 is characterized in that, between any two adjacent cells of said the first half, adopts the structure of common edge.

3. the level field head coil that is used for magnetic resonance imaging system according to claim 2 is characterized in that, the intersection of 4 unit of said the first half adopts 4 electric capacity bridge architectures.

4. the level field head coil that is used for magnetic resonance imaging system according to claim 3 is characterized in that, said the first half and the latter half surround two and open that tubular coil or one open, draw in the other end or the tubular coil of sealing.