초록 ▼

Magnetic apparatus for MRI/MRT probes and methods for construction thereof are disclosed. One embodiment includes a pair of opposed magnet assemblies defining an open region therebetween, a transmitting RF coil having at least a portion thereof disposed within the open region, at least one receiving

Magnetic apparatus for MRI/MRT probes and methods for construction thereof are disclosed. One embodiment includes a pair of opposed magnet assemblies defining an open region therebetween, a transmitting RF coil having at least a portion thereof disposed within the open region, at least one receiving RF coil disposed within the open region and X, Y and Z gradient coils. At least one of the X, Y and Z gradient coils is disposed outside of the open region. Another embodiment of the apparatus includes a single magnet assembly having a first surface and a second surface opposing the first surface, a transmitting RF coil having at least a portion thereof opposing the first surface, at least one receiving RF coil and X, Y and Z gradient coils. At least one of the X, Y and Z gradient coils opposes the second surface. In another embodiment the magnet assembly generates a permanent z-gradient magnetic field and therefore includes only X and Y gradient coils, at least one of which opposes the second surface. The apparatuses may also include one or more shim coils.

대표청구항 ▼

Magnetic apparatus for MRI/MRT probes and methods for construction thereof are disclosed. One embodiment includes a pair of opposed magnet assemblies defining an open region therebetween, a transmitting RF coil having at least a portion thereof disposed within the open region, at least one receiving

Magnetic apparatus for MRI/MRT probes and methods for construction thereof are disclosed. One embodiment includes a pair of opposed magnet assemblies defining an open region therebetween, a transmitting RF coil having at least a portion thereof disposed within the open region, at least one receiving RF coil disposed within the open region and X, Y and Z gradient coils. At least one of the X, Y and Z gradient coils is disposed outside of the open region. Another embodiment of the apparatus includes a single magnet assembly having a first surface and a second surface opposing the first surface, a transmitting RF coil having at least a portion thereof opposing the first surface, at least one receiving RF coil and X, Y and Z gradient coils. At least one of the X, Y and Z gradient coils opposes the second surface. In another embodiment the magnet assembly generates a permanent z-gradient magnetic field and therefore includes only X and Y gradient coils, at least one of which opposes the second surface. The apparatuses may also include one or more shim coils. t terminal of said nonreciprocal circuit element, having a characteristic impedance less than 50 ohms, and matching the characteristic impedance of said amplifying element to the characteristic impedance of said nonreciprocal circuit element; and a dielectric substrate to which said first connective conductor is attached as a transmission line and on which said amplifying element and said nonreciprocal circuit element are located adjacent to each other and connected through said first connective conductor, said dielectric substrate being mountable on a circuit substrate. 2. The radio-frequency composite element according to claim 1, including a circuit substrate on which said dielectric substrate is mounted. 3. The radio-frequency composite element according to claim 1, further comprising a coupled circuit connected to said first connective conductor. 4. The radio-frequency composite element according to claim 1, wherein said nonreciprocal circuit element is an isolator. 5. The radio-frequency composite element according to claim 1, wherein said cover of said amplifying element and said shield of said nonreciprocal circuit element are integral. 6. The radio-frequency composite element according to claim 1, wherein the dielectric substrate has a concave portion in which at least one of a body part and a body assembly part may be embedded, including a bottom, of at least one of said nonreciprocal circuit element and said amplifying element. 7. The radio-frequency composite element according to claim 1, wherein said dielectric substrate includes resin layers embedding both said nonreciprocal circuit element and said amplifying element. 8. The radio-frequency composite element according to claim 1, wherein said dielectric substrate is attached laterally to said nonreciprocal circuit element and to said amplifying element. 9. The radio-frequency composite element according to claim 1, comprising a plurality of dielectric substrates attached to tops and bottoms of said nonreciprocal circuit element and said amplifying element, wherein one of a top and a bottom dielectric substrate comprises a transmission line. 10. The radio-frequency composite element according to claim 1, wherein said transmission line is a triplet strip line. 11. The radio-frequency composite element according to claim 1, wherein said input terminal of said nonreciprocal circuit element and said first connective conductor are integral. 12. The radio-frequency composite element according to claim 11, comprising a plurality of said first connective conductors. 13. The radio-frequency composite element according to claim 1, further comprising a resin structure in which said body assembly of said nonreciprocal circuit element is held, wherein said resin structure extends toward said amplifying element and holds the body of said amplifying element. 14. The radio-frequency composite element according to claim 1, wherein said nonreciprocal circuit element is a circulator, and said radio-frequency composite element comprises a terminating resistor and a second connective conductor for connecting said terminating resistor to said circulator. 15. The radio-frequency composite element according to claim 14, wherein said terminating resistor has a cooling edge in contact with said shield. 16. The radio-frequency composite element according to claim 14, further comprising a detection circuit connected to said second connective conductor. 00, Malmstrom et al., 333/219.1