- Evolution Colonic Uncovered Controlled-Release Stent
Non-clinical testing has demonstrated that the Evolution® Colonic Stent is MR Conditional according to ASTM F2503. A patient with this stent can be scanned safely anytime after placement under the following conditions
- Static magnetic field of 3.0 Tesla or less.
- Spatial magnetic gradient field of 720 Gauss/cm. Non-clinical evaluation was conducted in a MR system (Excite, General Electric Healthcare) with a maximum spatial magnetic gradient field of 720 Gauss/cm as measured with a gaussmeter in the position of the static magnetic field pertinent to the patient (i.e., outside of scanner covering, accessible to a patient or individual).
MRI-Related HeatingImage Artifacts
1.5 and 3.0 Tesla Systems: It is recommended to scan in normal operation mode (whole body averaged specific absorption rate (SAR) = 2.0W/kg) (âNormal Operating Modeâ is defined as the mode of operation of the MR system in which none of the outputs have a value that cause physiological stress to the patient) for 15 minutes of scanning (i.e., per scanning sequence).
1.5 Tesla Temperature Rise
In non-clinical testing, the Evolution® Colonic Stent produced maximum temperature rises of 1.9°C during 15 minutes of MR imaging (i.e., for one scanning sequence) performed in a 1.5 Tesla MR System (Magnetom, Siemens Medical Solutions, Malvern, PA, Software Numaris/4, Version Syngo MR 2002B DHHS Active-shielded) at an MR system reported whole-body-averaged SAR of 2.9 W/kg (associated with a calorimetry measured whole body averaged value of 2.1 W/kg).
3.0 Tesla Temperature Rise
In non-clinical testing, the Evolution® Colonic Stent produced maximum temperature rises of 2.7°C during 15 minutes of MR imaging (i.e., for one scanning sequence) performed in a 3 Tesla MR System (Excite, HDx, General Electric Healthcare, Milwaukee, WI, Software 14X.M5) at an MR system reported whole-body-averaged SAR of 2.9 W/kg (associated with a calorimetry measured whole body averaged value of 2.7 W/kg).
MR image quality may be compromised if the area of interest is in within the lumen or within approximately 3 mm of the position of the Evolution® Colonic Stent, as found during non-clinical testing using the sequence: T1-weighted, spin echo and gradient echo pulse sequence in a 3.0 Tesla MR system (Excite, General Electric Healthcare, Milwaukee, WI, Software 14X.M5). Therefore, it may be necessary to optimize MR imaging parameters for the presence of this metallic stent.
Additional Information: The safety of performing an MRI procedure in a patient with overlapping colonic stents or other MRI-conditional device(s) in direct contact with this device has not been determined. Performing MRI in such situations is not recommended.
For US Patients Only
Cook recommends that the patient register the MR conditions disclosed in this IFU with the MedicAlert Foundation. The MedicAlert Foundation can be contacted in the following manners:
Mail: MedicAlert Foundation International
2323 Colorado Avenue
Turlock, CA 95382
Phone: 888.633.4298 (toll free)
209.668.3333 from outside the U.S.
Fax: 209.669.2450 Web: www.medicalert.org