Koninklijke Philips Corporation N.V.

Gösta J Ehnholm

Erkki Tapani Vahala

Mika Petri Ylihautala

Seppo T Vahasalo

Fiducials () are disposed in an imaging region () along with a subject. The fiducials are mounted either to the subject itself, a surgical tool (), an imaging probe or receive coil (), or the like. The fiducials are filled with a liquid or gel of a fluorine 19 (Fl) compound which has a resonance frequency that is only 6% off from the resonance frequency of protons. This enables a common transmitter (), transmit and receive coils, and receiver () to be utilized for both proton and fluorine 19 imaging. The proton and fluorine resonance signals are separately reconstructed into corresponding image memories (). From the positions of the fiducials, a position calculator () determines the position of a fiducial carrying surgical tool or probe relative to the proton image. A depiction of the tool or probe from a look-up table () is appropriately positioned and rotated () and superimposed on the proton image by a video processor ().

Fiducial markers for MRI

A wireless remote control unit () that operates in the radio frequency bandwidth is used for interfacing with a sequence control system (B) and an image processing system (C) from within a magnetic resonance suite (A) in the presence of a magnetic field produced by a main magnet assembly (). The sequence control system and the image processing system are connected with a first wireless transceiver () whose antenna () is located within a magnetic resonance suite. The first transceiver () communicates with the remote control unit () and a second transceiver () connected with a transmitter () and gradient coil amplifiers (). Resonance signals received by a radio frequency coil () are communicated to the first transceiver () by the second transceiver () or by a transceiver (') mounted on the receiving coil. The receiver coil transceiver also engages in a handshake protocol to identify itself.

Growing community of inventors

Helsinki, Finland

Gösta J Ehnholm