US 6,636,040 B1 · MRI antenna

Abstract

An MRI antenna is disclosed comprising a first coaxial cable unit comprising a first inner conductor with first and second ends and a first outer conductor substantially surrounding the inner conductor. The first outer conductor has first and second ends. The first coaxial cable unit has a concave curvature facing a first direction. A second coaxial cable unit is provided comprising an inner conductor with first and second ends and an outer conductor substantially surrounding the inner conductor. The outer conductor has first and second ends and the second coaxial cable unit has a concave curvature facing a second direction opposite the first direction. The concave curvature of the first and second coaxial cable units generally face each other to define a region for receiving a body part. The first end of the first inner conductor is connected to the first end of the second inner conductor through a first capacitor. The first end of the first outer conductor is connected to the first end of the second outer conductor through a second capacitor. The second end of the first inner conductor and the second end of the second inner conductor are not connected to each other and the second end of the first outer conductor and the second end of the second outer conductor are not connected to each other. The first and second outer conductor provide an output of the antenna. Additional coaxial cable units may be electrically connected to the first or second coaxial cable units. An antenna array of five coaxial cable units is disclosed for imaging the lumbar spine. Transmitting antennas and magnetic resonance imaging systems are also disclosed.

Claims46

Dependent claims

An MRI antenna comprising:

a first coaxial cable unit comprising a first inner conductor with first and second ends and a first outer conductor substantially surrounding the first inner conductor, the first outer conductor having first and second ends, the first coaxial cable unit having a concave curvature facing a first direction;
and
a second coaxial cable unit comprising a second inner conductor with first and second ends and a second outer conductor substantially surrounding the inner conductor, the second outer conductor having first and second ends, the second coaxial cable unit having a concave curvature fig a second direction opposite the first direction;
wherein:
the concave curvature of the first and second coaxial cable units generally face each other to define a region between the first and second coaxial cable units for receiving a body part,
the first end of the first inner conductor is to be electrically connected to the first end of the second inner conductor through a first capacitor and the first end of the first outer conductor is to be electrically connected to the first end of the second outer conductor through a second capacitor,
the second end of the first inner conductor and the second end of the second inner conductor are unconnected to each other and the second end of the first outer conductor and the second end of the second outer conductor being unconnected to each other, and
first and second outer conductors provide an output of the antenna.

5 more elements

An MRI antenna comprising:

first second and third coaxial cable units, each coaxial cable unit comprising inner and outer conductors, wherein each outer conductor substantially surrounds each inner conductor and the inner and outer conductors of each coaxial cable unit are inductively coupled during operation;
the first, second and third coaxial cable units lying in first, second and third parallel plants, respectively, the first plane being between the second and third planes and the first and third coaxial cable units being aligned;
the first second and third coaxial cable units having a concave curvature, wherein the curvature of the first and third coaxial cable units is in a first direction and the curvature of the seconds coaxial cable unit is in a second direction opposite the first direction, the first, second and third coaxial cable units defining a region for receiving a body part;
the second coaxial cable unit having portions adjacent to the first and third coaxial cable units, for inductively coupling the second coaxial cable unit to the first and third coaxial cable units, during operation;
the inner and outer conductors of the first and third coaxial cable units being electrically coupled to form respective circuits tuned to the same frequency;
the inner conductors of the first and third coaxial cable units being capacitively coupled to the inner conductor of the second coaxial cable unit through a single capacitive connection and the outer conductors of the first and third coaxial cable units being capacitively coupled to the outer conductor of the second coaxial cable unit through a single capacitive connection;
the antenna further comprising outputs from the coupled outer conductors of the first and third coaxial cable units and from the outer conductor of the second coaxial cable unit.

4 more elements

An MRI antenna comprising:

first, second, third, fourth and fifth coaxial cable units, each coaxial cable unit comprising inner and outer conductors, wherein the outer conductor substantially surrounds the inner conductor and the inner and outer conductors of each coaxial cable unit are inductively coupled during operation;
the first, second, third, fourth and fifth coaxial cable units lying in first, second, third, fourth and fifth parallel planes, respectively, the first plane being between the third and fourth planes and the second plane being between the fourth and fifth planes;
the first and second coaxial cable units being aligned and the third, fourth and fifth coaxial cable units being aligned;
the first, second, third, fourth and fifth coaxial cable units each having a concave curvature, wherein the curvature of the first and second coaxial cable units is in a first direction and the curvature of the third, fourth and fifth coaxial cable units is in a second direction opposite the first direction, the first, second, third, fourth and fifth coaxial cable units defining a region for receiving a body part;
the first coaxial cable unit having portions adjacent to the third and fourth coaxial cable units for inductively coupling the first coaxial cable unit to the third and fourth coaxial cable units, during operation;
the second coaxial cable unit having portions adjacent to the fourth and fifth coaxial cable units for inductively coupling the second coaxial cable unit with the fourth and fifth coaxial cable units during operation;
the inner and outer conductors of the first and second coaxial cable units being electrically connected to form respective circuits tuned to a frequency and the inner and outer conductors of the third, fourth and fifth coaxial cable units being electrically connected to form respective circuits tuned to the frequency;
the inner conductors of the first and third coaxial cable units being capacitively coupled to the inner conductors of the third, fourth and fifth coaxial cable units through a single capacitive connection and the outer conductors of the first and second coaxial cable units being capacitively coupled to the outer conductors of the third, fourth and fifth coaxial cable units through a single capacitive connection;
and
the antenna further comprising an output from the outer conductors of the first and third coaxial cable units and from the outer conductors of the third, fourth and fifth coaxial cable units.

7 more elements

An MRI antenna comprising:

a support;
first, second, third, fourth and fifth coaxial cable units supported by the support in first, second, third, fourth and fifth parallel planes, respectively, the first plane being between the third and fourth planes and the second plane being between the fourth and fifth planes, each coaxial cable unit comprising inner and outer conductors inductively coupled during operation;
each coaxial cable unit comprising generally parallel leg portions and a transverse portion connecting the leg portions, each coaxial cable unit being supported by the support such that the first and second coaxial cable units are aligned and the third, fourth and fifth coaxial cable units are aligned to define a region for receiving a body part;
wherein the leg portions of the first coaxial cable unit extend between the leg portions of the third and fourth coaxial cable units and the leg portions of the second coaxial cable unit extend between the leg portions of the fourth and fifth coaxial cable units for inductively coupling the first coaxial cable unit to the third and fourth coaxial cable unit and for inductively coupling the second coaxial cable unit to the third and fourth coaxial cable units during operation;
the inner conductors of the first and second coaxial cable units being electrically connected to form a circuit tunable to a frequency;
the outer conductors of the first and second coaxial cable units being electrically connected to form a circuit tunable to the frequency;
the inner conductors of the third, fourth and fifth coaxial cable units being electrically connected to form a circuit tunable to the frequency;
and
the antenna further comprising outputs from the circuit comprising the outer conductors of the first and second coaxial cable units and from the circuit comprising the outer conductors of the third, fourth and fifth coaxial cable units.

6 more elements

An MRI antenna comprising:

a support;
first, second, third, fourth and fifth coaxial cable units supported by the support in first, second, third, fourth and fifth parallel planes, respectively, the first plane being between the third and fourth planes and the second plane being between the fourth and fifth planes, each coaxial cable unit comprising inner and outer conductors inductively coupled during operation;
each coaxial cable unit comprising generally parallel leg portions and a transverse portion connecting the leg portions, each coaxial cable unit being supported by the support such that the first and second coaxial cable units are aligned and the third, fourth and fifth coaxial cable units are aligned,
wherein the leg portions of the first coaxial cable unit extend between the leg portions of the third and fourth coaxial cable units and the leg portions of the second coaxial cable unit extend between the leg portions of the fourth and fifth coaxial cable units for inductively coupling the first coaxial cable unit to the third and fourth coaxial cable units and for inductively coupling the second coaxial cable unit to the third and fourth coaxial cable units during operation, respectively;
wherein each inner and outer conductor has a first and second end, the first end of each inner and outer conductor of each coaxial cable unit being on a first side of the antenna and the second end of each inner and outer conductor of each coaxial cable unit being on a second side of the antenna, opposite the first side;
and
the first end of the inner conductor of the first coaxial cable unit is directly electrically connected to the first end of the inner conductor of the second coaxial cable unit;
the first end of the outer conductor of the first coaxial cable unit is directly electrically connected to the first end of the outer conductor of the second coaxial cable unit;
the second end of the inner conductor of the first coaxial cable unit is electrically connected to the second end of the inner conductor of the second coaxial cable unit through a capacitor;
the second end of the outer conductor of the first coaxial cable unit is electrically connected to the second end of the outer conductor of the second coaxial cable unit through a capacitor;
the first ends of the inner conductors of the third, fourth and fifth coaxial cable units are directly electrically connected in parallel;
the first is of the outer conductors of the third, fourth and fifth coaxial cable units are directly electrically connected in parallel;
the second ends of the inner conductors of the third, fourth and fifth coaxial cable units are electrically connected in parallel through at least one capacitor;
the second ends of the outer conductors of the third, fourth and fifth coaxial cable units a electrically connected in parallel through at least one capacitor;
the electrically connected first ends of the inner conductors of the first and second coaxial cable units are electrically connected to the electrically connected first ends of the inner conductors of the third, fourth and fifth coaxial cable units through a capacitor;
and
the electrically connected second ends of the outer conductors of the first and second coaxial cable units are electrically connected to the electrically connected second ends of the outer conductors of the third, fourth and fifth coaxial cable units through a capacitor, providing an output of the antenna.

14 more elements

Dependencies are inferred from the claim text.

MRI antenna

Life of this patent

MRI antenna

Life of this patent

Abstract

Claims46