Patent ID: 7064549
Filing Date: 2006-06-20
Classification: G01R

Abstract:
1. A nuclear magnetic resonance apparatus comprising a nuclear magnetic resonance radio-frequency coil, the coil comprising: a distributed-capacitance central coil structure comprising a pair of longitudinally-spaced conductive rings including a first band-shaped ring and a second band-shaped ring, wherein a coil window is defined in a space between the first ring and the second ring, and a plurality of longitudinal conductive segments each electrically interconnecting the first ring to the second ring; a first ring-shaped capacitance band overlapping the first ring and having a first diameter; and a second ring-shaped capacitance band, wherein the second capacitance band has a second diameter substantially equal to the first diameter, is situated adjacent to the first ring-shaped capacitance band on the same side of the coil window as the first capacitance band and distant from the coil window, and is longitudinally-movable between a proximal position and a distal position, the distal position being situated further away from the coil window than the proximal position, wherein the second capacitance band in the proximal position overlaps the first ring, and wherein longitudinally moving the second capacitance band tunes a resonance frequency of the coil.