An Evaluation of MRI Safety and Compatibility of a Silver-Impregnated Antimicrobial Wound Dressing

Purpose

Wound infections can slow healing, increase pain, and have negative effects on a patient's quality of life. The recent emergence of antibiotic-resistant bacterial strains has led wound care specialists to revisit alternative topical agents such as silver to control wound bioburden. Aquacel Ag is an ionic silver-containing barrier dressing that is able to absorb large amounts of wound exudate. The aim of this study was to assess the magnetic resonance (MR) safety and compatibility of this dressing, according to the standard requirements of the American Society for Testing and Materials (ASTM).

Methods

Radiofrequency-induced temperature changes associated with the test dressing were assessed using an ASTM phantom at 123 and 64 MHz. Whether the dressing caused any image distortion or magnetic deflection or if the electric resistance of the hydrated dressing differed significantly from that of tissue was also investigated.

Results

Similar radiofrequency-induced temperature changes were observed during 123 MHz (nominal 3 T) MR imaging of the phantom material alone (1.3°C) and when the dressing was added (1.8°C-2.0°C). Similar increases in temperature were also observed at 64 MHz (1.5 T) in the phantom material alone (1.4°C-1.9°C) and with the dressing (1.6°C-1.7°C). The test dressing did not cause any discernible image distortion or magnetic deflection and had similar electric resistance to human body tissues.

Conclusion

The wound dressing impregnated with ionic silver evaluated in this study has similar magnetic and electric characteristics to human tissues and is MR safe as defined in ASTM standard F2503-05. Therefore, the dressings can be left in place when a patient is undergoing MR imaging.

Key Words: Silver, antimicrobial, wound dressing, magnetic resonance imaging