WO2013017043A1

WO2013017043A1 - Horizontal field head coil for use in magnetic resonance imaging system

Info

Publication number: WO2013017043A1
Application number: PCT/CN2012/079255
Authority: WO
Inventors: 罗伟平
Original assignee: 苏州众志医疗科技有限公司
Priority date: 2011-08-01
Filing date: 2012-07-27
Publication date: 2013-02-07
Also published as: CN102305917A

Abstract

A horizontal field head coil for use in a magnetic resonance imaging system, comprising eight annular units and divided into an upper part and a lower part. The upper part and the lower part respectively are provided with four units in a two-by-two arrangement. The four units of the upper part respectively have a portion of circuit arranged at the lower part. The head coil has a simple structure, a great signal-to-noise ratio, and provides patients with a great field of vision.

Description

A horizontal field head line for magnetic resonance imaging systems

Technical field

The invention belongs to the field of magnetic resonance imaging, and in particular relates to a horizontal field head line for a magnetic resonance imaging system.

Background technique

The magnetic resonance imaging system can be classified into a horizontal field magnetic resonance system and a vertical field magnetic resonance system according to the magnetic field direction of the main magnet. The horizontal field system refers to the direction of the magnetic field of the magnet parallel to the human torso, pointing from the brain to the footstep or vice versa. The vertical field system means that the direction of the magnetic field of the magnet is perpendicular to the direction of the human torso, such as from the front of the person to the back. The magnetic field direction of the magnet is the most important reference for designing the RF line, because the antenna elements in the turns need to be as vertical as possible to achieve the best RF excitation or reception. Sensitivity (or more generally, signal-to-noise ratio) and uniformity are the two most important metrics in terms of RF 圏 performance. From the perspective of doctor's ease of operation and patient comfort, the RF headline 圏 has an important function of opening up and down the two parts, because the patient's head can be conveniently placed into the sputum. In addition, in order to reduce the claustrophobia of some patients, the head line should have as open a field as possible. Finally, because the head line can be used for neurocognitive research experiments, such experiments often require visual stimulation of the subject, and the open field of view is also an indispensable condition for the head line. There are currently two classic commercial RF headlines in the MRI market. One is the Siemens 12-channel headline and the other is the 8-channel headline from Invivo. The Siemens 12-channel line uses a 2 x 6 antenna unit layout, as shown in Figure 1; the Invovo 8-channel line unit layout is shown in Figure 2. Siemens' 12-channel line is divided into completely independent upper and lower parts, chl-ch6 is the upper part, and ch7-chl2 is the lower part. The upper part can be removed from it, and the upper part is covered after the patient is lying down. The dotted line in Figure 1 is the patient's field of view. Such a design has a defect in which four channels chl, ch3, ch4, ch6 in the upper half and four channels ch7, ch9, chl0, chl2 in the lower half have four adjacent groups of cells chl /ch7, ch3/ch9, ch4/chl0, ch6/chl2 can not take decoupling measures, which will cause the signal-to-noise ratio of these 8 channels to be greatly affected, and ultimately affect the signal-to-noise ratio of the entire line. Invivo's 8-channel line 圏 does not have a separate structure in the upper part, and the dotted line area is the patient's field of view. Although this design does not affect the signal-to-noise ratio of the turns, it does not have the separation function of the upper and lower halves. It is inconvenient for the patient to lie in or out of the line. In addition, because the middle beam is too large, it also partially affects the patient's field of vision.

Summary of the invention

The object of the present invention is to provide a horizontal field head line for a magnetic resonance imaging system with a good patient vision and high signal to noise ratio. The technical solution of the present invention is:

A horizontal field head 圏 for a magnetic resonance imaging system, comprising: 8 annular units divided into upper and lower parts, and the upper half and the lower half each having 4 units arranged in a 2 x 2 arrangement; Each of the four units in the upper half has a part of the circuit placed in the lower half.

Further, between the two adjacent units in the upper half, the structure of the common side is used.

Further, the upper half of the four cells are connected by four capacitor bridge structures.

Further, the upper half and the lower half are enclosed by a tubular coil which is opened at both ends or a tubular coil which is opened at one end and which is closed or closed at the other end.

The advantages of the invention are:

1. The 8 antenna unit signals in the upper and lower parts can be output together from the lower half to maximize the convenience of 8-way signals output together;

2. It can be opened up and down to facilitate the patient to lie in;

3. Among the four units in the upper part, any two units can be well decoupled, and the signal-to-noise ratio is significantly optimized.

4. Minimize the area of the patient's visual field disorder and optimize the patient's field of vision. DRAWINGS

The present invention is further described below in conjunction with the accompanying drawings and embodiments:

Figure 1 shows the layout of the antenna unit of the Siemens 12-channel coil;

Figure 2 shows the antenna unit layout of the Invovo 8-channel cable ;;

3 is an antenna unit layout of an 8-channel coil of the present invention;

Figure 4 is a perspective view of an embodiment of an 8-channel coil of the present invention;

Figure 5 is a perspective view of an embodiment of an 8-channel turn of the present invention;

Figure 6 is a comparison of the image SNR of the 8-channel headline 圏 and the 12-channel headline 圏 of the present invention. detailed description

Embodiments: The horizontal field head line for the magnetic resonance imaging system shown in FIG. 3 includes upper and lower portions that are not completely independent, wherein the upper half is a portion sandwiched between two left and right broken lines, including units chl, ch4 , ch5, ch8; The lower half includes the units ch2, ch3, ch6, ch7; the upper half of the four units chl, ch4, ch5, ch8 have one side in the lower half. The upper part can be removed from it, and the upper part is covered after the patient is lying down. The upper part chl, ch4, ch5, Ch8 between any two adjacent units, the structure of the common side: unit ch4 and ch8 share one side, there is a capacitor c9 on the side; unit ch8 and ch5 share one side, there is a capacitor clO on the side; unit ch5 and chl share one On the side, there is a capacitor c11 on the side; the cells chl and ch4 share one side with a capacitor cl2 on the side. The junction of the four units in the upper part uses four capacitive bridge structures: Capacitors c3, c4, c5 and c6 form a capacitive bridge structure. The horizontal field head 圏 for the magnetic resonance imaging system of the present invention can be expanded into a cylindrical or elliptical cylindrical or square tubular horizontal field line 圏, as shown in FIG. 4 and FIG. Opening the tubular loop or one opening and the other closing the tubular thread are two embodiments of the present invention. According to the above structure, an 8-channel 1.5T horizontal field head line 制作 was fabricated, and the test result is shown in Fig. 6. The solid line curve is from the 8-channel line 本 of this embodiment, and the dotted line comes to a certain Siemens production and sales. Since the 12-channel turns, the two heads have the same inner diameter. The ordinate SNR is a ratio, dimensionless. The abscissa is the distribution of pixel points. The actual picture is 256*256 pixels. In Figure 6, only the most representative middle line is taken out. This line consists of 256 points. As can be seen from the above two pictures, the 8-channel line has a significant signal-to-noise ratio advantage over the 12-channel line, and the image is more uniform. The test results show that the wire has excellent performance, good signal-to-noise ratio and uniformity, can be opened up and down, the patient has a good view, and all the 8 signals are output from the lower half, which is convenient for system connection. The present invention is compared with the existing horizontal field head line as follows:

The above embodiments are only one of the embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

Rights request

A horizontal field head 圏 for a magnetic resonance imaging system, comprising: 8 annular units divided into upper and lower parts, 4 of which are arranged in a 2 x 2 arrangement in the upper half and the lower half Unit; Each of the four units in the upper half has a part of the circuit placed in the lower half.

2. The horizontal field head line for a magnetic resonance imaging system according to claim 1, wherein a structure of a common side is used between any two adjacent units in the upper half.

3. The horizontal field head 圏 for a magnetic resonance imaging system according to claim 2, wherein the upper half of the four cells are connected by four capacitive bridge structures.

4. The horizontal field head enthalpy for a magnetic resonance imaging system according to claim 3, wherein the upper half and the lower half are enclosed by two ends of a cylindrical wire loop or one head is opened, and the other head is closed. Or a closed tubular thread.