Extended-coverage imaging coil
Extended-coverage magnetic resonance imaging coils with optimized homogeneity in longitudinal sensitivity are described. One exemplary coil includes four elements, where two of the elements are opposed-solenoid imaging elements and two of the elements are single loop imaging elements.
1. A magnetic resonance imaging (MRI) coil configured to be positionable by a catheter that is operably connectable to an MRI apparatus, the coil comprising:
one or more capacitors configured to facilitate one or more of, tuning the MRI coil to the Lamor frequency, and matching the MRI coil to a receiver in the MRI apparatus;
one or more detuning elements;
two opposed-solenoid imaging elements positioned along the longitudinal axis of the catheter and being substantially perpendicular to the longitudinal axis, the two opposed-solenoid imaging elements being separated by a gap region with a current being driven in opposite directions in the opposed-solenoid imaging elements on either side of the gap region; and
one or more single loop imaging elements positioned along the longitudinal axis of the catheter, being substantially parallel to the longitudinal axis, and outside the gap region;
the two opposed-solenoid imaging elements, the one or more single loop imaging elements, and the one or more capacitors forming a circuit,
the two opposed-solenoid imaging elements and the one or more single loop imaging elements being positioned relative to each other and with respect to the longitudinal axis of the catheter to produce a sensitivity profile that is radially homogenous.
2. The MRI coil of claim 1 , the MRI apparatus is employed in an intravascular imaging application.
3. The MRI coil of claim 1 , the MRI coil is configured to selectively provide low resolution survey imaging and high resolution examination imaging.
4. The MRI coil of claim 1 , the two opposed-solenoid imaging elements comprising two or more windings of copper magnet wire with a pitch spacing of about one copper magnet wire diameter.
5. The MRI coil of claim 1 , the MRI coil is configured as a multi-channel coil.
6. The MRI coil of claim 1 , where the one or more single loop imaging elements comprise two single loop imaging elements wound in the same direction.
7. The MRI coil of claim 1 , where the one or more single loop imaging elements comprise two counter-wound single loop imaging elements.
8. The MRI coil of claim 1 , the one or more single loop imaging elements each having a long axis length between 6.5 mm and 16.5 mm, a short axis length approximately equal to a diameter of a wire used to form one of the two opposed-solenoid imaging elements, and a separation distance between 0 mm and 6.5 mm from at least one of the two opposed-solenoid imaging elements.
9. The MRI coil of claim 1 , the total length of the MRI coil is less than 22 mm.
10. A magnetic resonance imaging apparatus configured with a catheter configured with the MRI coil of claim 1 .
11. A magnetic resonance imaging (MRI) coil configured to be positionable by a catheter that is operably connectable to an MRI apparatus employed in an intravascular imaging application, the coil comprising:
one or more capacitors configured to facilitate one or more of, tuning the MRI coil to the Lamor frequency, and matching the MRI coil to a receiver of the MRI apparatus;
one or more detuning elements;
two opposed-solenoid imaging elements positioned along the longitudinal axis of the catheter and being substantially perpendicular to the longitudinal axis, the two opposed-solenoid imaging elements being separated by a gap region with a current being driven in opposite directions in the opposed-solenoid imaging elements on either side of the gap region; and
one or more single loop imaging elements positioned along the longitudinal axis of the catheter and outside the gap region, being substantially parallel to the longitudinal axis, each having a long axis length between 6.5 mm and 16.5 mm, a short axis length approximately equal to the diameter of a wire used to form one of the two opposed-solenoid imaging elements, and a separation distance between 0 mm and 6.5 mm from at least one of the two opposed-solenoid imaging elements;
the two opposed-solenoid imaging elements, the one or more single loop imaging elements, and the capacitor forming a circuit,
the two opposed-solenoid imaging elements and the one or more single loop imaging elements being positioned relative to each other and with respect to the longitudinal axis of the catheter to produce a sensitivity profile that is radially homogenous,
the MRI coil being configured to selectively provide low resolution survey imaging and high resolution examination imaging, and
the MRI coil being configured as a multi-channel coil that facilitates selectively performing parallel imaging.