Methods and apparatus for magnetic resonance imaging with RF coil sweeping

A moveable radio-frequency (RF) receiving coil assembly for receiving RF signals generated by nuclear magnetization excited by a magnetic resonance (MR) apparatus in a region of interest in an object to be examined comprising:

• manipulation means for manipulating the moveable RF receiving coil assembly,
• an RF receiving coil for receiving RF imaging signals,
• at least three MR-active microcoils for receiving MR position signals generated simultaneously by said nuclear magnetization from which the 3D spatial coordinates of the microcoils can be determined repetitively during the period of receiving the RF imaging signals, wherein at least three of the microcoils are non-collinearly arranged, and
• signal lines for connecting the RF receiving coil and the microcoils to RF receivers in the MR apparatus.

An magnetic resonance (MR) apparatus for MR imaging of a region of interest in an object to be examined comprising:

• a main field magnet for generating a steady magnetic field in the region of interest,
• a magnetic field gradient system for generating gradients in the steady magnetic field in the region of interest,
• a radio-frequency (RF) transmitter for transmitting RF pulses to the region of interest,
• an RF receiving coil assembly comprising:
• manipulation means for manipulating the RF receiving coil assembly,
• an RF receiving coil for receiving MR imaging signals from the region of interest,
• at least three MR-active microcoils for simultaneously receiving MR position signals from which the 3D spatial coordinates of the microcoils can be determined, wherein at least three of the microcoils are non-collinearly arranged, and
• signal lines for connecting the RF receiving coil and the microcoils to the MR apparatus,
• means for detecting the received MR imaging signals and the received MR position signals,
• control means responsive to the detected MR imaging signals and the detected MR position signals for controlling the RF transmitter, the magnetic field gradient system, and the means for detecting to (i) excite nuclear magnetization in the region of interest by applying RF pulses and magnetic field gradients according to a selected imaging protocol and to detect MR imaging signals received in the RF receiving coil, (ii) determine repetitively 3D positions and 3D orientations of the RF receiving coil from the detected MR position signals which are simultaneously and repetitively generated during the period of receiving the MR imaging signals, wherein during the period of receiving the MR imaging signals the RF receiving coil is swept near the region of interest, and (iii) to reconstruct an MR image of the region of interest from the received MR imaging signals and from the determined 3D positions and 3D orientations of the RF receiving coil.