Vertical magnet apparatus suitable for MRI

Abstract: In order to give a physician easy access to a patient placed in an interjacent space within a vertical magnet apparatus of a vertical magnet-type MRI apparatus, support and movement mechanisms (19) are provided on respective opposing surface sides of a pair of vertical opposing magnets (11), for supporting a cradle or a seat of a chair on belts (18), and moving the cradle or the seat in the horizontal direction by motors (17) and in the vertical direction by hydraulic cylinders (13).

Description: The present invention relates to vertical magnet apparatus suitable for MRI (magnetic resonance imaging) which is improved to give a physician (or operator) easy access to a patient (or subject) placed in an interjacent space within the vertical magnet apparatus. Figure 1 is a perspective view illustrating a main portion of an exemplary vertical magnet-type MRI apparatus, such as those disclosed in Japanese Patent Application JP11 206 733 (published on 03.08.99). The vertical magnet-type MRI apparatus 900 comprises a vertical magnet apparatus 50 consisting of a pair of vertical opposing magnets 11 whose opposing surfaces stand vertically, and a table apparatus 90 having a table 91 which can be hydraulically moved upward and downward and a non-magnetic cradle 22 which can be moved forward and backward in the horizontal direction by a motor. The vertical magnet apparatus 50 is provided with up/down buttons 50ud for moving the table 91 upward and downward, and in/out buttons 50io for moving the cradle 22 forward and backward to positions inside and outside of an interjacent space of the vertical magnet apparatus 50. The "interjacent space" used herein designates a space between the vertical opposing magnets 11. In the conventional vertical magnet-type MRI apparatus 900, the table 91 is extended into the interjacent space of the vertical magnet apparatus 50 so that the cradle 22 can be moved in and out of the interjacent space of the vertical magnet apparatus 50. However, as shown in Fig. 2, the table 91 extending into the interjacent space obstructs easy access by a physician (or operator) D to a patient (or subject) in the interjacent space. It is an object of the present invention to provide an MRI vertical magnet apparatus which is improved to give a physician (or operator) easy access to a patient (or subject) in an interjacent space within the vertical magnet apparatus. This is achiered with an apparatus according to claim 1. It has been delimited with respect to an apparatus as disclosed, for instance, in EP-A-0 424 808. Preferred embodiments are set forth in the dependent claims. Thus, according to the MRI vertical magnet apparatus and the MRI apparatus of the present invention, the following advantages can be obtained: Because the support and movement means is provided on each of the opposing surface sides of the pair of vertical opposing magnets, for supporting the cradle or the seat of the chair and moving the cradle or the seat of the chair in the horizontal or vertical direction, the need to extend the obstructive table into the interjacent space is eliminated, thereby giving the physician (or operator) easy access to the patient (or subject) in the interjacent space. Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings, in which: Figure 1 is a schematic perspective view of a conventional vertical magnet-type MRI apparatus. Figure 2 illustrates the problem of the conventional vertical magnet-type MRI apparatus. Figure 3 is a schematic perspective view of a vertical magnet-type MRI apparatus in accordance with a first embodiment of the present invention. Figure 4 is a cross sectional view showing imaging of the head by the vertical magnet-type MRI apparatus of Fig. 3. Figure 5 is a cross sectional view showing imaging of the loins by the vertical magnet-type MRI apparatus of Fig. 3. Figure 6 is a cross sectional view showing joint motion imaging of the cervical vertebrae by the vertical magnet-type MRI apparatus of Fig. 3. Figure 7 is a cross sectional view showing joint motion imaging of the knee joint by the vertical magnet-type MRI apparatus of Fig. 3. Figure 8 is a cross sectional view showing another example of the support and movement mechanism. Figure 9 is a schematic perspective view of a vertical magnet-type MRI apparatus (no embodiment of the present invention). Figure 10 is a cross sectional view showing imaging of the head by the vertical magnet-type MRI apparatus of Fig. 9. Figure 11 is a cross sectional view showing joint motion imaging of the cervical vertebrae by the vertical magnet-type MRI apparatus of Fig. 9. The present invention will now be described in more detail with reference to embodiments shown in the accompanying drawings. Figure 3 is a schematic perspective view of a vertical magnet-type MRI apparatus in accordance with the present invention. The vertical magnet-type MRI apparatus 100 comprises a vertical magnet apparatus 10. Further, the figure shows a table apparatus 20 and a chair apparatus 30. The vertical magnet apparatus 10 comprises a pair of vertical opposing magnets 11 whose opposing surfaces stand vertically, a laterally spaced pair of support and movement mechanisms 12 disposed on the respective opposing surface sides of the pair of vertical opposing magnets 11. Each of the support and movement mechanisms 12 comprises a pair of hydraulic cylinders 13, 13, a non-magnetic base panel 14 which is supported by the hydraulic cylinders 13, 13 so that it can be moved upward and downward, a multiplicity of non-magnetic rollers 15 and a pair of pulleys 16, 16, each pivoted to the base panel 14, a motor 17 attached to the pulley 16, a belt 18 fitted over the rollers 15 and the pulleys 16, and a non-magnetic connecting block 19 secured to the belt 18. One of the vertical opposing magnets 11 is provided with up/down buttons 10ud for moving the base panels 14 upward and downward by the hydraulic cylinders 13, and in/out buttons 10io for moving the connecting blocks 19 forward and backward in the horizontal direction by circulating the belts 18 by the motors 17. The table apparatus 20 comprises a table 21 which can be moved upward and downward by a motor, a non-magnetic cradle 22 which can be moved forward and backward in the horizontal direction by a motor, wheels 23 for movement, connecting pins 24 which protrude from the front end of the cradle 22 and can be coupled with the connecting blocks 19, and a detach lever 25 for detaching the cradle 22 from the table 21. The table 21 is provided with up/down buttons 20ud for moving the table 21 upward and downward, and in/out buttons 20io for moving the cradle 22 forward and backward to move the cradle 22 onto and off of the table 21. The chair apparatus 30 comprises a base portion 31, a seat 32 removably attached to the base portion 31, wheels 33 for movement, connecting pins 34 which protrude from the front end of the seat 32 and can be coupled with the connecting blocks 19, and a detach lever 35 for detaching the seat 32 from the base portion 31. The base portion 31 is provided with up/down pedals 30ud for moving the seat 32 upward and downward. Figure 4 illustrates imaging of the head of a subject H using the table apparatus 20. The up/down buttons 10ud of the vertical magnet apparatus 10 are operated to adjust the height of the belts 18 to a height suitable for imaging. The in/out buttons 10io are also operated to place the connecting blocks 19 at positions closest to the table apparatus 20. The up/down buttons 20ud of the table apparatus 20 are then operated to adjust the cradle 22 to a height aligned with the belts 18. The in/out buttons 20io are also operated to advance the cradle 22 toward the connecting blocks 19 and join the connecting pins 24 to the connecting blocks 19. Next, the in/out buttons 10io of the vertical magnet apparatus 10 are operated to draw the cradle 22 connected to the connecting blocks 19 into the interjacent space within the vertical magnet apparatus 10 and align the head of the subject H with a magnet center C. Under this condition, the head of the subject H is imaged. At this time, as shown in Fig. 4, the physician D can enter a space between the pair of the support and movement mechanisms 12 and has easy access to the patient H, thereby enabling interventional examinations such as centesis while viewing a captured MRI image. Moreover, as shown in Fig. 5, by operating the detach lever 25 of the table apparatus 20 to detach the cradle 22 from the table 21 and transfer the cradle to the support and movement mechanisms 12, and then moving the table apparatus 20 (excluding the cradle 22) away, a large space can be secured to give the physician D easy access to the patient H from the side on which the table apparatus 20 would otherwise be positioned. In addition, instruments for the interventional examination can be conveniently arranged. Figure 6 illustrates joint motion imaging of the neck of the subject H using the chair apparatus 30. The up/down buttons 10ud of the vertical magnet apparatus 10 are operated to adjust the height of the belts 18 to a height suitable for imaging. The in/out buttons 10io are also operated to place the connecting blocks 19 at positions closest to the chair apparatus 30. The up/down pedals 30ud of the chair apparatus 30 are then operated to adjust the seat 32 to a height aligned with the belts 18. The chair apparatus 30 is then moved to join the connecting pins 34 of the seat 32 to the connecting blocks 19. Next, the detach lever 35 of the chair apparatus 30 is operated to detach the seat 32 from the base portion 31 and transfer the seat 32 to the support and movement mechanisms 12, and then the chair apparatus 30 (excluding the seat 32) is moved away. Then, the in/out buttons 10io of the vertical magnet apparatus 10 are operated to draw the seat 32 connected to the connecting blocks 19 into the interjacent space within the vertical magnet apparatus 10 and align the neck of the subject H with the magnet center C. Then, as shown in Fig. 6, the operator D can enter a space between the pair of the support and movement mechanisms 12 and has easy access to the patient H, thereby enabling suitable joint motion imaging of the neck of the subject H. Furthermore, as shown in Fig. 7, when the knee of the subject H is aligned with the magnet center C, joint motion imaging of the knee of the subject H can be suitably performed. As in the exemplary variation shown in Fig. 8, it is possible to employ a vertical magnet apparatus 10' comprising support and movement mechanisms 12' for achieving upward and downward movement by means of chains 13' circulated by a motor. Figure 9 is a schematic perspective view of a vertical magnet-type MRI apparatus which is no embodiment of the present invention. The vertical magnet-type MRI apparatus 200 comprises a vertical magnet apparatus 50 consisting of a pair of vertical opposing magnets 11 whose opposing surfaces stand vertically, and a table apparatus 40 having a table 41 which can be hydraulically moved upward and downward and a non-magnetic cradle 22 which can be moved forward and backward in the horizontal direction by a motor. The vertical magnet apparatus 50 is provided with up/down buttons 50ud for moving the table 41 upward and downward, and in/out buttons 50io for moving the cradle 22 forward and backward to move the cradle 22 in and out of the interjacent space within the vertical magnet apparatus 50. The table 41 of the table apparatus 40 is extended into the interjacent space of the vertical magnet apparatus 50 so that the cradle 22 can be moved in and out of the interjacent space of the vertical magnet apparatus 50. A portion extending into the interjacent space is bifurcated to form a bifurcated arm portion 43 defining a space for access 44. Figure 10 illustrates imaging of the head of the subject H. The up/down buttons 50ud of the vertical magnet apparatus 50 are operated to adjust the cradle 22 to a height suitable for imaging. The in/out buttons 50io are also operated to draw the cradle 22 into the interjacent space within the vertical magnet apparatus 10 and align the head of the subject H with a magnet center C. Under this condition, the head of the subject H is imaged. At this time, as shown in Fig. 10, the physician D can enter the space for access 44 within the bifurcated arm portion 43 and has easy access to the patient H, thereby enabling interventional examinations such as centesis while viewing a captured MRI image. Furthermore, as shown in Fig. 11, if a seat 62 is attached at the front end of the cradle 22, the imaging can be performed with the subject H in a sitting position. This is suitable for joint motion imaging of, for example, the neck.

Claims: Apparatus for MRI including a pair of vertical magnets (11) having vertically oriented opposing surfaces disposed to have a space therebetween, the apparatus being characterised by a laterally spaced pair of support and movement mechanisms (12) disposed on the respective opposing surfaces, each of the support and movement mechanisms comprising (i) a non-magnetic base panel (14) disposed inside said space and adjacent a respective one of said opposing surfaces, supported by a respective pair of hydraulic cylinders (13) or a respective pair of vertical posts (13') containing chains which can be circulated by a motor, so that the base panel (14) can be moved upward and downward, (ii) a multiplicity of non-magnetic rollers (15) and a pair of pulleys (16), each pivoted to the base panel (14), (iii) a motor attached to one of the pulleys (16), (iv) a belt (18) fitted over the rollers (15) and the pulleys (16) to be moved thereby, (v) and a non-magnetic connecting block (19) secured to the belt (18) for coupling a cradle (22) or a seat of chair, respectively, to move the cradle or seat horizontally and/or vertically. The apparatus of claim 1, comprising a table (20) with a separate non-magnetic cradle (22) for holding horizontal a patient or subject to be examined, the cradle (22) being movable forward and backward; a plurality of wheels (23) for movement of the table; pins (24) protruding from a front end of the cradle (22) for coupling with said connecting blocks (19). The apparatus of claim 1, comprising a separate chair (30) for a patient to be examined, which is movable into said space between the vertical magnets (11), said chair comprising a base portion (31), a seat (32) removably attached to the base portion (31), wheels (33) for movement of the base portion (31), connecting pins (34) protruding from a front end of the seat (32) for coupling with said connecting blocks (19).

Inventors: HAYAKAWA KAZUHIKO, HAYASHI YUJIRO, NOSE KATSUMASA, HAYAKAWA, KAZUHIKO, HAYASHI, YUJIRO, NOSE, KATSUMASA
Applicants: YOKOGAWA MEDICAL SYST, GE YOKOGAWA MEDICAL SYSTEMS, LTD.
Application year: 1999
Main classification: G01R33
IPC codes: G01R33, A61B5, G01N24