5210494 Sample head for nuclear magnetic resonance whole-body tomography or localized in-vivo nuclear magnetic resonance spectroscopy

Abstract

A sample head (50) for nuclear magnetic resonance whole-body tomography or localized in-vivo nuclear magnetic resonance spectroscopy comprises an RF coil (51) having a plurality of inductive sections in the form of metallic strips (53 to 60) and capacitive sections in the form of gaps (61 to 68) arranged alternately one behind the other in the direction of the RF current (I 1 ), so that the field lines (72) of the magnetic RF field (H 1 ) generated by the RF coil (51) extend in parallel to an axis (74) defined by the RF coil (51). The RF coil (51) forms a single unit with an outer jacket (52). The number of inductive and capacitive sections is such as to be just below that limit value above which the distribution of the field lines (71) of the electric RF field (E 1 ) produced by the said RF coil (51) changes from a first distribution (75), where there is a plane (76) between each inductive section (55) and the said axis (74) in which the strength of the electric RF field (E 1 ) is equal to zero, to a second distribution where the strength of the said electric RF field (E 1 ) rises in a substantially rotationally symmetrical pattern around the said axis, and linearly from the said axis toward the said RF coil, and this irrespective of the number of inductive sections present.