A system for cardiac and respiratory gating of a magnetic resonance imager

Abstract
A cardiac and respiratory gating system is described which minimises MRI distortion by using a commercially available pneumatic capsule for respiration sensing, and by isolating the ECG and respiration detector circuitry with a fibre-optic link. Operator use is facilitated by displaying, on the ECG trace, the time during the cardiac cycle when images are acquired, and by displaying the respiratory signal. The system is presently in use with a MD 800 MRI system (M&D Technology Ltd., Aberdeen) operating at 0.08 tesla.