Radio frequency coil for open magnetic resonance imaging system

A quadrature coil for operation at a radio frequency in an open MRI system, the MRI system having a polarizing magnet with opposed pole faces for establishing therebetween a polarizing field axis (B0), the coil comprising:

• a first conductor array providing separated and substantially parallel conductor elements positioned along a first conductor axis extending across the polarizing field axis to opposed connection points;
• a second conductor array providing separated and substantially parallel conductor elements positioned along a second conductor axis extending across the polarizing field axis and substantially perpendicular to the first conductor array to opposed connection points;
• an RF shield positioned between an adjacent pole face and the first and second conductor arrays for providing a conductive surface interrupted by channels substantially aligned with both the first and second conductor axis;
• and
• a combiner/splitter electrically communicating with a connection point of each of the first and second conductor arrays to join the connection points with a signal line so that the signal path between said signal line and the connection point of the first conductor array has a substantially 90 degree phase when compared with the signal path between the common signal line and the connection point of the second conductor array.

A quadrature coil set for operation at a radio frequency in an open MRI system, the MRI system having a polarizing magnet with opposed pole faces for establishing therebetween a polarizing field axis, the coil comprising:

• A.) a first quadrature coil positioned at a first pole face and having
• (a) a first conductor array providing separated and substantially parallel conductor elements positioned along a first conductor axis extending across the polarizing field axis to opposed connection points, and
• (b) a second conductor array providing separated and substantially parallel conductor elements positioned along a second conductor axis extending across the polarizing field axis to opposed connection points in a direction substantially perpendicular to the first conductor array;
• B.) a second quadrature coil positioned at a second pole face and having:
• (a) a third conductor array providing separated and substantially parallel conductor elements positioned along the first conductor axis extending across the polarizing field axis to opposed connection points,
• (b) a fourth conductor array providing separated and substantially parallel conductor elements positioned along the second conductor axis extending across the polarizing field axis to opposed connection points in a direction substantially perpendicular to the first conductor array;
• C.) interconnection leads connecting the first and third conductor arrays in series through their connection points;
• and
• D.) interconnection leads connecting the second and fourth conductor arrays in series through their connection points;
• whereby current flow direction through the first and third conductor arrays is opposite to current flow direction through the second and fourth conductor arrays, respectively.