Positioning the ECG Lead Cable and wECG Module for Scanning
Expression MR400 Instructions for Use Monitoring ECG 5‐19
Selecting Monitor as the Filter Mode for the scan sequence; see page 5‐31.
Scan sequence parameters.
Improper connection of ECG lead cable to Quadtrode electrode contact locations.
Routing the ECG lead cable adjacent to the body coil or underneath an extremity coil.
Excessive distance between electrodes when using CV Quadtrode electrodes.
When applying electrodes or connecting the ECG lead cable, ensure that the electrodes
or connectors never contact other conductive materials including grounded
conductors. In order to prevent contact with other conductors or earth ground, make
sure all the electrodes or connectors are properly attached to the patient.
No other electrical conductors (e.g. wires, leads, probes, et cetera) should be placed
within the MRI bore at the same time as the ECG lead wires. Electrode heating risk
increases when multiple conductive cables and probes are placed in the bore with the
patient. Mixing of conductors from various manufacturers (catheters, temperature
sensors, et cetera) is not recommended. Multiple electrical conductors within the MRI
bore can allow cross-coupling between these various conductors, and appear as a large
antenna for RF energy pick-up, which will result in electrode heating, and possibly
skin burns. It is always important to identify if the patient has any metallic wires,
conductors, implants, stents, et cetera. within their body which will act as cross-
coupling conductors. If these are present, ECG monitoring may not be able to be
performed without experiencing electrode heating. Non-conductive tubes, air-lines, et
cetera—including NIBP cuffs and hoses, EtCO2 and/or oxygen air-lines, and SpO2
probes—can be used safely as these items do not include electrically conductive
materials. The MR400 has been validated for use with all accessories specified in the
accessory list; see page 1-33.
Circular, U-shaped or S-shaped loops in the ECG lead cable should be avoided to
reduce the risk of heating.
Do not use the Velcro storage strap to loop the ECG lead cable during MR scanning;
otherwise, there is a risk of cable heating and possibly skin burns.