Installation of the Centering Tube

The Centering Tube is used to mount and fixate the MRI CryoProbe™ coil head in the magnet bore.

The animal cradle is to be inserted from the animal preparation end and is directed and positioned by the Centering Tube.

The fixation of the Centering Tube depends on the size of the magnet bore, the gradient system and on the presence of a CCM cabinet. Therefore, the mounting process varies.

Generally, the Centering Tube is a straight tube of the length of the magnet with adjustable holders. It should not contact the gradient system to avoid transfer of vibrations while scanning. It is supported at both ends of the magnet.

 

Centering Tube installed.

 

A three-claw fastener holds the Centering Tube at the service end of the magnet. Since the water hoses and cables for the gradient are also leaving the gradient tube on the service end, the claw may be turned in any orientation such that is does not interfere with the water hoses or cables.

Install it as shown below and center the holding for the Centering Tube.

 

Three-claw fastener at the Service End.

 

NOTE
The correct position of the coil head within the magnet iso center is given by the Centering Tube which is adjusted during the installation. You may check the position by measuring a Localizer scan. If the coil is not centered at the iso center of the magnet axis, it may be readjusted by turning the screw between the two cylinders (with the measuring rod on it) at the front end of the Centering Tube. Use the non-magnetic screwdriver which was delivered with the CryoProbe.

 

 

On the preparation table end of the magnet, install the front fixation and insert the Centering Tube.

Clamp ring installed at the preparation end of the magnet. The clamp ring may remain installed even when no CryoProbe is in use.

 

Insert the Centering Tube from the preparation end of the magnet.

 

When inserted, the Centering Tube will fit into the adapter at the service end.

View within the CCM cabinet: The Centering Tube (1) is inserted into the adapter (2) which is assembled with the guide (3) and three-claw fastener. The rear of the gradient coil (4) shown looks different in the various instruments (example of B-GA6S-100 gradient coil in an 11 cm inner bore magnet).

 

Finally, tighten the Centering Tube with the screws at the clamp ring.

Centering Tube installed and fixated with the screws at the clamp ring.