Magnetic resonance imaging apparatus
View Patent ↗A magnetic resonance imaging apparatus includes a static magnetic field magnet which generates a static magnetic field, a gradient coil unit which generates a gradient magnetic field for overlapping with the static magnetic field, a shim unit which is disposed between the static magnetic field magnet and the gradient coil unit to control the static magnetic field, and a heat shielding member which is disposed between the gradient coil unit and the shim unit to shield a radiant heat of the gradient coil unit.
1. A magnetic resonance imaging apparatus comprising:
a static magnetic field magnet which generates a static magnetic field;
a gradient coil unit which generates a gradient magnetic field for overlapping with the static magnetic field;
a shim unit which is disposed between the static magnetic field magnet and the gradient coil unit to control the static magnetic field; and
a heat shielding member which is disposed between the gradient coil unit and the shim unit to shield a radiant heat of the gradient coil unit.
2. The magnetic resonance imaging apparatus according to claim 1 , wherein the shim unit is formed so that at least one magnetic shim is disposed.
3. The magnetic resonance imaging apparatus according to claim 1 , wherein the heat shielding member has a metal sheet of which a thickness is not more than a skin depth at a frequency of a gradient magnetic pulse which is supplied to the gradient coil unit.
4. The magnetic resonance imaging apparatus according to claim 3 , wherein the heat shielding member is formed so that a plurality of the metal sheets are laminated with an insulation sheet interposed therebetween.
5. The magnetic resonance imaging apparatus according to claim 1 , further comprising:
a cooling unit which cools the gradient coil unit.
6. The magnetic resonance imaging apparatus according to claim 5 , wherein the gradient coil unit has the cooling unit disposed therein.
7. The magnetic resonance imaging apparatus according to claim 1 , wherein the gradient coil unit is disposed in a vacuum state.
8. A magnetic resonance imaging apparatus comprising:
a static magnetic field magnet which generates a static magnetic field;
a gradient coil unit which generates a gradient magnetic field for overlapping with the static magnetic field;
a transmission coil which transmits a high-frequency pulse; and
a heat shielding member which is disposed between the gradient coil unit and the transmission coil to shield a radiant heat of the gradient coil unit and to shield the high-frequency pulse.
9. The magnetic resonance imaging apparatus according to claim 8 , wherein the heat shielding member has a metal sheet of which a thickness is not more than a skin depth at a frequency of a gradient magnetic pulse which is supplied to the gradient coil unit and of which the thickness is not less than a skin depth at a frequency of the high-frequency pulse.
10. The magnetic resonance imaging apparatus according to claim 9 , wherein the heat shielding member is formed so that a plurality of the metal sheets are laminated with an insulation sheet interposed therebetween.
11. The magnetic resonance imaging apparatus according to claim 8 , further comprising:
a cooling unit which cools the gradient coil unit.
12. The magnetic resonance imaging apparatus according to claim 11 , wherein the gradient coil unit has the cooling unit disposed therein.
13. The magnetic resonance imaging apparatus according to claim 8 , wherein the gradient coil unit is disposed in a vacuum state.