CN2348383Y - Nuclear magnetic resonance imaging probe - Google Patents

Abstract

The utility model discloses a nuclear magnetic resonance imaging probe, especially suitable for nuclear magnetic resonance imaging of laser intensified polarized air 129 Xe. The utility model comprises a sizing tube, a protecting barrel, a support frame, and an LC high-frequency oscillation loop. The utility model is characterized in that a coil is a saddle-shaped coil which symmetrically wraps on one end of the sizing tube; distance between circles is even; a fixed capacitor and an adjustable capacitor are evenly aligned on the other end of the sizing tube; the coil is in head-to-tail connection; the fixed capacitor is connected with the adjustable capacitor in parallel and is connected with two taps of the coil in parallel, forming the high-frequency oscillation loop; the adjustable capacitor is arranged between a core wire of a coaxial cable and one end of the high-frequency oscillation loop; the other end of the high-frequency oscillation loop is connected with a shield wire of the coaxial cable, forming a matching loop. The utility model which has the advantages of simple structure, easy fabrication, and convenient operation of tuning is suitable for laser polarized air 129 Xe.

Description

A kind of Magnetic resonance imaging probe

The utility model relates to a kind of Magnetic resonance imaging probe, is specially adapted to laser intensified polarization gas ¹²⁹The Magnetic resonance imaging of Xe.

A kind of new focus in the Magnetic resonance imaging was exactly a laser intensified polarization gas in recent years ¹²⁹The Magnetic resonance imaging research of Xe, and the Magnetic resonance imaging probe of some common element of equipping on the present commodity NMR imaging instrument all can not satisfy ¹²⁹The imaging requirements of Xe is as used on Bruker Biospec 47/30 NMR imaging instrument ¹The nmr frequency of H imaging coil probe is 200MHz, ¹²⁹The Xe nmr frequency is 55.4MHz on the NMR imaging instrument in 4.7T magnetic field, and other imaging coil probe of equipping on the imager can not satisfy on frequency ¹²⁹The requirement of Xe Magnetic resonance imaging.As the imaging probe of using on the NMR imaging instrument, a high frequency LC tuned circuit is all arranged, inductance element in the circuit generally be by a kind of specific around to coil or the no magnetic sheet metal of special type make, the size of coil and winding directly influence the radio-frequency field of probe, and arranging also of tuned circuit is influential to the Q value of probe, sensitivity etc.As the spiral cast imaging coil, at interval evenly, make it have good radio-frequency field homogeneity and high Q value between the circle of this coil, structure is also simple, but the RF magnetic direction that itself produces is not suitable for ¹²⁹Xe uses on Bruker Biospec 47/30 NMR imaging instrument.Alderman-Grand formula imaging probe and for example, it forms inductance element by two or four I-shaped no magnetic sheet metals of symmetry, connect many group adjustable condensers or fixed condenser between the sheet metal, though it has good imaging homogeneity, also can accomplish higher sensitivity and bigger size, but requiring has accurate adjusting symmetry, the adjustable or fixed condenser of one group of a plurality of equivalence, tuning making inconvenience.Other has a kind of birdcage imaging probe, coil coiled cage shape, and at interval evenly, field uniformity is good between the coil, but tuning capacitor is connected between the coil making inconvenience.Also have a kind of saddle type coil probe, forms by two groups of symmetry saddle type coils, every group 1 circle-2 circles, tuning capacitor or link near coil is perhaps pulled out the outer tuning influence with the minimizing distributed capacitance of probe core.This sonde configuration is simple, but the Q value is difficult to do height, is generally used for analysis of spectrum or the imaging of reduced size sample in the nuclear magnetic resonance spectrometer.

The purpose of this utility model provides a kind of probe of Magnetic resonance imaging easily simple in structure, tuning, has solved laser intensified polarization gas ¹²⁹The Magnetic resonance imaging of Xe.

The technical solution of the utility model is: this utility model by sizing tube, LC high-frequency tuning loop, casing, be configured to.It is characterized in that the coil in LC high-frequency tuning loop is by the end of two groups of saddle type coil symmetries around sizing tube, every group around 3 to 5 circles, even at interval between circle and the circle.This alignment of tuned circuit capacitor is made of fixed condenser and two adjustable condensers, be evenly arranged in the other end of sizing tube, the center of coil, and a suitable distance is arranged between the tuning capacitor, cause the spectral line phase distortion to prevent RF magnetic field from producing inhomogeneous.Two groups of coils in this loop join end to end, and two taps are in parallel with fixed condenser respectively, and are in parallel with an adjustable condenser again, insert another adjustable condenser between the heart yearn of parallel circuit and concentric cable, are used to adjust the coupling of probe and imager.The screen layer of another termination concentric cable of parallel circuit, the shielding layer grounding of concentric cable.Above-mentioned sizing tube and LC high-frequency tuning loop have constituted the probe core, outside the probe core organic glass casing, protection coil and oscillation circuit element are arranged.Respectively there is a support at the casing two ends, support is made by round organic glass sheet, the disk central axis has circular hole, diameter and sizing tube external diameter coincide, disk external diameter and casing internal diameter match, two end supports are by the fixing sizing tube of center pit, and constitute together with casing and wholely to be connected and to fix, and make imaging coil be positioned at the magnetic field center of NMR imaging instrument superconducting magnet.Also have the circular hole of two embedding adjustable condensers on the support disk of tuning capacitor one end, both the stationary adjustable capacitor was convenient to tuner operation again.

Fig. 1 is the structural representation of a kind of Magnetic resonance imaging probe of the utility model

Fig. 2 is that the high-frequency tuning loop of a kind of Magnetic resonance imaging probe of the utility model links synoptic diagram

According to Fig. 1,2 as can be known, determine coil L by sizing tube 1 ₁, L ₂Size.By coil L ₁, L ₂, fixed condenser C ₁, C ₂, adjustable condenser C ₃, C ₄Constitute LC high-frequency tuning loop.Coil L in this loop ₁, L ₂Be the saddle type coils of two groups of symmetries around sizing tube one end, use smooth no magnetic metal wire, as silver-gilt copper wire, every group of coil encloses around 3-5 respectively.Coil L ₁, L ₂Join end to end.Fixed condenser C ₁, C ₂(nominal value is 331M) series connection links back and adjustable condenser C ₃(nominal value 5640JOHASON) parallel connection, the circuit that is constituted again with coil L ₁, L ₂Two tap parallel connections.Coil L ₁, L ₂, fixed condenser C ₁, C ₂, adjustable condenser C ₃Constitute oscillation circuit.Insert adjustable electric 6 container C between the heart yearn of one end in this loop and 50 Ω output concentric cable 5 ₄(nominal value 5640JOHASON), its effect is the coupling of regulating probe and NMR imaging instrument.The shielding line of another termination concentric cable 5 of this loop, the shielding line ground connection of concentric cable 5.Fixed condenser C ₁, C ₂, adjustable condenser C ₃, C ₄Be evenly arranged in the other end of sizing tube, with coil L ₁, L ₂Centre distance be the 70-90 millimeter, organic glass casing 2 is enclosed within by sizing tube 1, coil L ₁, L ₂, fixed condenser C ₁, C ₂, adjustable condenser C ₃, C ₄Outside the probe core that constitutes, protection coil and oscillation circuit element.Support 3,4 is made by organic glass, and external diameter and casing 2 internal diameters coincide, and open a circular hole in central axis, and its internal diameter and sizing tube 1 external diameter coincide, and fixedly sizing tube 1, thus assurance imaging coil L ₁, L ₂Be positioned at the magnetic field center of NMR imaging instrument superconducting magnet.On support 4, also have two embedding adjustable condenser C ₃, C ₄Hole and a hole that passes for concentric cable 5.Casing 2 and support 3, support 4 and probe core constitute the probe one-piece construction together.

Simple in structure according to the imaging probe that said structure is made, to make easily, cost is low, and tuner operation is convenient.On Bruker Biospec 47/30 NMR imaging instrument, be used for laser intensified polarization gas ¹²⁹The Magnetic resonance imaging of Xe.Natural Xe gas of high pressure and laser intensified polarization low pressure have been measured ¹²⁹Xe gas core magnetic resonance spectrum, relaxation time and physical parameter, laser-polarization low pressure (15Torr) gas of gained ¹²⁹The signal to noise ratio (S/N ratio) of Xe NMR signal is 145; Obtain ¹²⁹9000 times of the laser enhancing multiples of Xe nuclear spin polarization, imaging the natural Xe gas of high pressure (6.5 atmospheric pressure).Use spectrum imaging method, imaging laser intensified polarization low pressure ¹²⁹Xe gaseous sample tubular axis to horizontal picture; Use the gtadient echo method, fast imaging Xe (622Torr)+N ₂+ Cs.

Claims (3)

1, a kind of Magnetic resonance imaging probe, it is made of sizing tube (1), LC high-frequency tuning loop, casing (2) and support (3), (4), it is characterized in that: coil L ₁, L ₂Be saddle type coil, symmetry is around an end of sizing tube (1), and distance is even between circle and the circle, fixed condenser C ₁, C ₂With adjustable condenser C ₃, C ₄Be evenly arranged in sizing tube (1) other end, coil L ₁, L ₂Join end to end fixed condenser C ₁, C ₂The series connection, and with adjustable condenser C ₃Parallel connection is again with coil L ₁, L ₂Two tap parallel connections, constitute high frequency oscillation circuit, insert adjustable condenser C4 between the heart yearn of an end in this loop and concentric cable (5), the shielding line of another terminated cable (5) in this loop links to each other, the composition matching circuit.

2, by the described a kind of Magnetic resonance imaging probe of claim 1, it is characterized in that: coil L ₁, L ₂The number of turns be 3-5 circle.

3, by the described a kind of Magnetic resonance imaging probe of claim 1, it is characterized in that: coil L ₁, L ₂Center and capacitor C ₁-C ₄Distance be the 70-90 millimeter.