MRI Compatibility (Investigational Device. Limited By Federal (United States) Law To Investigational Use)

Non-clinical testing has demonstrated that the Crux VCF Filter is MR-Conditional. Patients with the Crux VCF can be scanned safely, immediately after placement of this implant, under the following conditions:

• Static magnetic field of 3-Tesla or 1.5-Tesla.
• Spatial gradient field of 40 mT/m or less.
• Maximum specific absorption rate (SAR) of 3.56 W/kg for 15 minutes of scanning at 3.0T.
• Maximum specific absorption rate (SAR) of 1.0 W/kg for 15 minutes of scanning at 1.5T.
• Normal operating mode of the MR system only.

In non-clinical testing, the Crux Biomedical VCF produced a temperature rise of less than or equal to 0.6°C at a maximum specific absorption rate (SAR) of 3.56 W/kg for 15 minutes of scanning in a 3-Tesla MR system (Siemens Trio, SYNGO MR A30 4VA30A software, Munich, Germany). Additionally, the Crux Biomedical VCF produced a temperature rise of less than or equal to 4.1°C at a maximum specific absorption rate (SAR) of 2.28 W/kg for 15 minutes of scanning in a 1.5-Tesla MR system (Siemens Espree, SYNGO MR B15 software, Munich, Germany). Therefore, scaling the SAR to 1.0 W/kg results in a theoretically calculated temperature rise of 1.8°C.

MR image quality may be compromised if the area of interest is in the exact same area or relatively close to the position of the Crux VCF. Therefore, it may be necessary to optimize MR imaging parameters for the presence of this metallic implant.

Physicians should encourage patients to register the above safe scanning conditions with MedicAlert Foundation (www.medicalert.org) or equivalent organization.