MR imaging and vascular access ports: ex vivo evaluation of ferromagnetism, heating, and artifacts at 1.5 T.

The purpose of our study was to assess ferromagnetism, heating, and artifacts associated with vascular access ports exposed to a 1.5-T MR system. Twenty-eight different vascular access ports were evaluated in this investigation. Ferromagnetism was determined by using two previously described techniques. Temperature changes were measured immediately before and after performing a pulse sequence on the vascular access ports for 60 min at a specific absorption rate of 3.1 W/kg. Artifacts were assessed in association with the use of a fast GRASS pulse sequence. None of the vascular access ports displayed ferromagnetism. Heating was 0.2 degrees C or less. The presence of artifacts varied, depending on the component materials. The lack of ferromagnetism and negligible heating indicates that MR imaging performed at 1.5 T or less may be conducted safely in patients with any of the vascular access ports tested. None of the associated artifacts produced by the vascular access ports is considered to pose a substantial problem for MR imaging.