摘要:
Magnetic resonance apparatus includes a magnet system (1) for generating a steady magnetic field in a measurement space (29), a coil system (3) for generating gradient fields in the measurement space, and at least one RF coil (9) which is accommodated in a housing (33) which can be arranged in the measurement space and which is suitable to accommodate an object (41 ) to be examined, and a jig for positioning an instrument (57) introduced into the object (41). This jig has a first stop (59) for defining the position of a free end of the instrument (57) in a first coordinate direction (Z) of a three-dimensional system of coordinates. The jig also has a perforated plate (55) which is provided with holes (53) which are arranged in a matrix which extends according to second and third coordinate directions (X, Y) of the coordinate system in order to position the instrument (57) in the second and third coordinate directions. The location of a coordinate axis extending parallel to the second or the third coordinate direction (X, Y) is defined by a first phantom (71) which is rigidly arranged in the housing (33).
摘要:
Magnetic resonance apparatus includes a main magnet system (1) for generating a steady magnetic field, a magnet system (3) for generating gradient fields, an RF transmitter coil (9) and an RF receiver coil system (13) which includes first and second RF coil systems (47, 49) for detecting resonance signals generated in respective first and second regions of an object to be arranged on a supporting face (43), said regions being adjacently situated in a first direction (57), each of the first and second RF coil systems comprising at least a surface coil. The apparatus is intended notably for the examination of the spine of a patient arranged on the supporting face (43), the first region containing the thoracic segment of the spine (T-spine) and the second region containing the lumbar segment (L-spine). In order to enable easy adaptation of the position of the second RF coil system (49) to the location of the L-spine of an individual patient, the first RF coil system (47) is arranged to be stationary relative to the supporting face (43) in a first coil plane (53) extending substantially parallel to the supporting face, whereas the second RF coil system (49) is arranged to as to be displaceable in the first direction (57) in a second coil plane (61) which extends parallel to the first coil plane (53).
摘要:
A jig for positioning an instrument, for example a biopsy needle, includes a stop (7) for defining the position of a free end (3) of the instrument in a first coordinate direction (Z) of a three-dimensional system of coordinates, and an adjusting mechanism (15, 17) for adjusting the position of the instrument in second (X) and third (Y) coordinate directions of the system of coordinates. The adjusting mechanism is accommodated in a housing (23) in which furthermore a phantom (5) is rigidly mounted. The adjusting mechanism includes a first and a second circular disc (15, 17), having a first and a second central axis (19, 21), respectively, each central axis extending perpendicularly to the plane of the relevant disc and through its center (16, 18). The first disc (15) is journalled in the housing (23) so as to be rotatable about the first central axis (19) and is provided with an eccentrically situated circular opening (27) whose diameter is substantially equal to the diameter of the second disc (17). The second disc (17) is journalled in said opening (27) so as to be rotatable about the second central axis (21). The first and second central axes (19, 21) extend parallel to the first coordinate direction (Z) and the first central axis intersects the plane of the second disc (17) at a distance (d) from the center (18) of the second disc which is smaller than the radius (r) of the second disc. At the same distance (d) from the center (18) a passage (29) is provided in the second disc (17), which passage is arranged to guide the instrument (1) in the first coordinate direction (Z).