Evaluation of infusion pump performance in a magnetic resonance environment

For use in a magnetic resonance (MR) scanning room infusion pumps must be MR safe and compatible. This study tested two commonly used infusion pumps (Alaris P6000 and Alaris Asena-GH) to determine if they met these criteria.

The pumps underwent testing within the scanning room of a 3 T MR scanner. Pump infusion rates were tested at up to 100 Gauss magnetic field strength, with and without radio frequency signals present. The effect of the pumps on image quality was assessed. The occlusion pressure alarm of the pumps was tested at up to 100 Gauss. The projectile risk was assessed by measuring the force exerted upon the pumps at the entrance to the scanner.

The maximum mean flow rate errors at 100 Gauss were 2.18% for the Alaris P6000 and 1.42% for the Alaris Asena-GH, both within our accepted limits. Radio frequency signals had no effect on flow rate. The pumps produced no discernable artefacts on the acquired images. The maximum mean occlusion pressure error was 204 mmHg higher for the Alaris P6000 pump and 99 mmHg lower for the Alaris Asena-GH (P-values < 0.001) at 100 Gauss compared to testing outside the scanner. Both pumps were subject to significant attractive force at the entrance to the scanner.

Whilst the pumps cannot strictly be termed MR safe or compatible at 100 Gauss we have demonstrated that flow rates are unchanged and that, for the Alaris Asena-GH, the effect on the occlusion pressure alarm is unlikely to have patient safety implications.