Abstract: In the magnetic resonance imaging device, the distance between the first and second coils is different in the circumferential direction and has a first region (A1) (?=0, ?) and a second region (A2) (?=?/2) narrower than the first region (A1). In the first coil, wiring patterns (17a, 17b) on the side of a zero-plane (F0) passing through the center of the first coil and perpendicular to the axis direction (z-axis direction) meander in the circumferential direction such that the wiring patterns (17a, 17b) depart from the zero-plane (F0) in the first region (A1) and approach the zero-plane (F0) in the second region (A2). This provides a gradient magnetic field coil capable of configuring wiring patterns without using a loop coil that does not pass through the z-axis.

Abstract: A coil unit comprises a gradient coil which is disposed along a static magnetic field generating source, and a radio frequency coil which is disposed along the gradient coil in a test region at a position closer to the center of the test region compared with the gradient coil, and a conductor part which is disposed between the gradient coil and the radio frequency coil, and covers periphery of the radio frequency coil. The radio frequency coil comprises a first loop coil and a second loop coil locating in planes substantially perpendicular to direction of the static magnetic field, a plurality of linear conductors connecting the first loop coil and the second loop coil and substantially parallel to the direction of the static magnetic field, and a plurality of first capacitors disposed in the first loop coil and the second loop coil.

Abstract: There is provided a coil unit having a large region of homogeneous sensitivity for the axial direction even with a shortened rung length of birdcage type RF coil. The coil unit comprises a gradient coil which is disposed along a static magnetic field generating source, and a radio frequency coil which is disposed along the gradient coil in a test region at a position closer to the center of the test region compared with the gradient coil, and a conductor part which is disposed between the gradient coil and the radio frequency coil, and covers periphery of the radio frequency coil. The radio frequency coil comprises a first loop coil and a second loop coil locating in planes substantially perpendicular to direction of the static magnetic field, a plurality of linear conductors connecting the first loop coil and the second loop coil and substantially parallel to the direction of the static magnetic field, and a plurality of first capacitors disposed in the first loop coil and the second loop coil.

Abstract: An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.

Abstract: An endoscope-like image taking method includes providing at least one peculiar index, which can be discriminated from other portions on an MR image, at the tip of a catheter, previously inserting a metal guide wire for guiding the catheter into a body cavity of a patient inserting the catheter into the body cavity along the guide wire, executing an MR imaging sequence of a plurality of sliced images intersecting the guide wire, reconstructing three-dimensional image data based upon the nuclear magnetic resonance signals, which are received by the guide wire, and determining the tip position and the inserting direction of the catheter by detecting the peculiar index provided at the tip of the catheter based upon the three-dimensional image data, and reconstructing the center projected image using the three-dimensional image data and setting the tip position and the inserting direction of the catheter as a view point and a line-of-sight direction and displaying the center projected image on a display means.

Abstract: The gradient coil for a magnetic resonance imaging apparatus is adapted to encode information on a spatial position of a subject to be inspected into a nuclear magnetic resonance signal. The gradient coil includes a primary gradient coil and a shielded gradient coil. The primary gradient coil generates a gradient magnetic field in the imaging area. The shielded gradient coil is located on the side opposite to the imaging area relative to the primary gradient coil and cancels the gradient magnetic field generated by the primary magnetic field. The shielded gradient coil has a first area including a central axis perpendicularly extending through the central portion of the imaging area and a second area located on the side of the outer circumference of the first area. The second area is more inclined toward the imaging area than the first area.

Abstract: An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.

Abstract: The gradient coil for a magnetic resonance imaging apparatus is adapted to encode information on a spatial position of a subject to be inspected into a nuclear magnetic resonance signal. The gradient coil includes a primary gradient coil and a shielded gradient coil. The primary gradient coil generates a gradient magnetic field in the imaging area. The shielded gradient coil is located on the side opposite to the imaging area relative to the primary gradient coil and cancels the gradient magnetic field generated by the primary magnetic field. The shielded gradient coil has a first area including a central axis perpendicularly extending through the central portion of the imaging area and a second area located on the side of the outer circumference of the first area. The second area is more inclined toward the imaging area than the first area.

Abstract: An MRI apparatus having a configuration that reduces vibration of a static magnetic field generating source is provided. A closed vessel 2 of the static magnetic field generating source is provided with a rigid structure 4 for preventing transmission of vibration generated from a gradient magnetic field generating part 21 to other members via the closed vessel 2. The rigid structure 4 uses, for example, a connecting part 4 that connects a face 25 on the imaging space side and a face 26 confronting it. The rigidity of the closed vessel is thereby increased, and therefore vibration transmitted from the gradient magnetic field generating part can be reduced. The connecting part can have a through-hole structure, and in such a case, internal space of through-hole can be used for drawing cables.

Abstract: A gradient coil apparatus for magnetic resonance imaging system includes a plurality of gradient coils 11a, 11b and 11c for applying a gradient magnetic field to a test object and an internal heat exchanger 14 to be immersed in insulation oil 13 in a container 12. A pump 16 is disposed to circulate coolant between the internal heat exchanger 14 and an external heat exchanger 15 is disposed outside of the container 12. This arrangement allows the insulation oil only inside of the container, thereby ensuring a substantial reduction in the amount of insulation oil.

Abstract: The present invention provides a gradient coil apparatus for magnetic resonance imaging system capable of enhancing electrical insulation performance and cooling performance. A gradient coil apparatus for magnetic resonance imaging system comprising plurality of gradient coils 11a, 11b and 11c for applying a gradient magnetic field to a test object and an internal heat exchanger 14 to be immersed in insulation oil 13 in a container 12. A pump 16 is disposed to circulate coolant between the internal heat exchanger 14 and an external heat exchanger 15 disposed outside of the container 12. This arrangement allows the insulation oil only inside of the container, thereby ensuring a substantial reduction in the amount of insulation oil.

Abstract: An MRI apparatus having a configuration that reduces vibration of a static magnetic field generating source is provided. A closed vessel 2 of the static magnetic field generating source is provided with a rigid structure 4 for preventing transmission of vibration generated from a gradient magnetic field generating part 21 to other members via the closed vessel 2. The rigid structure 4 uses, for example, a connecting part 4 that connects a face 25 on the imaging space side and a face 26 confronting it. The rigidity of the closed vessel is thereby increased, and therefore vibration transmitted from the gradient magnetic field generating part can be reduced. The connecting part can have a through-hole structure, and in such a case, internal space of through-hole can be used for drawing cables.

Abstract: The present invention is intended to provide a magnetic pole, a magnet apparatus, and a magnetic resonance imaging apparatus that the magnetic structure of the magnet apparatus for generating a uniform magnetic field is formed in a lower burst mode, and the profitability is increased, and at the same time, the uniformity of the magnetic field is improved. According to the present invention, the magnetic poles arranged opposite to each other across a measuring space have at least one of a plurality of hollows and a single hollow having a shape continuously changing on the section perpendicular to the direction of the magnetic field formed in the measuring space and particularly in order to make the magnetic field uniform, the arrangement of the plurality of hollows and the shape of the single hollow are adjusted. The magnet apparatus and magnetic resonance imaging apparatus of the present invention are structured as mentioned above.

Abstract: To reduce vibration and noise generated in supplying pulsatile current to the gradient magnetic field coil for driving that coil in a MRI apparatus, an active shielded gradient magnetic field coil is used, in which the gradient magnetic field coil is supported by and fixed to the static magnetic field generating magnet. The supporter for supporting this gradient magnetic field coil in non-contact does not prevent the interventional procedure performed by a doctor. Further, an eddy current generated on the surface of the static magnetic field generating magnet near the periphery of the gradient magnetic field coil, when supplying the pulsatile current to the gradient magnetic field coil, can be reduced.

Abstract: A magnet device provided with a shield current carrying means in which two sets of magneto-static field generating sources for generating magnetic fields directed towards a first direction are disposed facing each other across a finite region and at least one set of the magneto-static field generating sources are disclosed on at least two almost concentric circles. A first plane includes a first axis, a second axis and a first point. The first point is a point of insertion between the first axis parallel to the first direction and passing almost through the center of the shield current carrying means. The second axis crosses at right angles to the first axis and is spaced almost equal distance from the two sets of the generating sources. The alternately arranged positive and negative current carrying directions of the shield current carrying means are set in the order of increasing value of ?n.

Abstract: An endoscope-like image taking method of the present invention includes a preparation step of providing at least one peculiar index, which can be discriminated from other portions on an MR image, at the tip of a catheter, a first step (S1) of previously inserting a metal guide wire for guiding the catheter into a body cavity of a patient into which the catheter is inserted, a second step (S2) of inserting the catheter into the body cavity along the guide wire, a third step (S3) of executing an MR imaging sequence of a plurality of sliced images intersecting the guide wire, a fourth step (S4) of reconstructing three-dimensional image data based upon the nuclear magnetic resonance signals, which are generated from the patient when the sequence is executed and are received by the guide wire, and determining the tip position and the inserting direction of the catheter by detecting the peculiar index provided at the tip of the catheter based upon the three-dimensional image data, and a fifth step (S5) of reconstru

Abstract: A magnet device includes two sets of static magnetic field generation sources spaced from each other in the vertical direction such that the uniform magnetic field region (patient space) is between then. Each set has concentric current carrying coils to generate a uniform magnetic field in a first direction (the vertical direction).

Abstract: To reduce vibration and noise generated in supplying pulsatile current to the gradient magnetic field coil for driving it in the MRI apparatus, the present invention discloses an active shielded gradient magnetic field coil, in which the gradient magnetic field coil is supported by and fixed to the static magnetic field generating magnet. The supporter for supporting this gradient magnetic field coil in non-contact does not prevent the interventional procedure performed by a doctor. Further, eddy current generated on the surface of the static magnetic field generating magnet near the periphery of the gradient magnetic field coil when supplying the pulsatile current to the gradient magnetic field coil can be reduced.

Abstract: A superconducting magnet apparatus. By forming one or more holes in each of platelike ferromagnetic substances forming a magnetic shield for focusing the magnetic flux generated by superconducting coils, the flow of lines of magnetic flux is adjusted. Thereby, a static magnetic field in a measurement space is corrected. By disposing coupling tubes for supporting two cooling vessels housing superconducting coils on the rear side with respect to a central axis (Z axis) of the measurement space of the vertical direction, access to the subject is facilitated. In addition, the magnetic shield has an opening portion wider than the superconducting magnet on its side face. After the magnetic shield has been assembled, the superconducting magnet can be inserted from the opening portion.

Abstract: The present invention is intended to provide a magnetic pole, a magnet apparatus, and a magnetic resonance imaging apparatus that the magnetic structure of the magnet apparatus for generating a uniform magnetic field is formed in a lower burst mode, and the profitability is increased, and at the same time, the uniformity of the magnetic field is improved.