MRI apparatus with a piezo actuator in a non-rigid suspension of the gradient coil carrier

A gradient coil system in an apparatus for forming magnetic resonance images, said gradient coil system comprising:

• a gradient coil carrier on which gradient coils are arranged;
• a gradient control circuit for producing a gradient signal for the gradient coil carrier;
• and
• a plurality of suspension elements for attaching the gradient coil carrier to a frame of the apparatus, each of said plurality of suspension elements being comprised of:
• a resilient element;
• an active drivable element that is connected in series with the resilient element;
• and
• a drive circuit for driving the active drivable element, said drive circuit being provided with a feedforward circuit which receives the gradient signal and predicts a negative value of a displacement in the gradient coil carrier caused by the gradient signal.

A gradient coil system in an apparatus for forming magnetic resonance images, said gradient coil system comprising:

• a gradient coil carrier on which gradient coils are arranged;
• and
• a plurality of suspension elements for attaching the gradient coil carrier to a frame of the apparatus, each of said plurality of suspension elements being comprised of:
• a resilient element;
• a vibration sensor provided at a point of attachment of the suspension element on the gradient coil carrier;
• an active drivable element that is connected in series with the resilient element;
• and
• a drive circuit for driving the active drivable element, said drive circuit being provided with a feedback circuit which receives a displacement signal from the vibration sensor and converts the received displacement signal into an appropriate control signal for the active drivable element.