On-X Ascending Aortic Prosthesis, Instructions For Use Manual

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On-X
®
Ascending Aortic Prosthesis IFU 15
English
10. POSTOPERATIVE INFORMATION
10.1 Magnetic Resonance Imaging (MRI) Compatibility
MR Conditional
The On-X Prosthetic Heart Valve, Conform-X Mitral Heart Valve
Prosthesis, Size 25-33* , was determined to be MR-conditional accord-
ing to the terminology specified in the American Society for Testing and
Materials (ASTM) International, Designation: F2503-08. Standard Practice
for Marking Medical Devices and Other Items for Safety in the Magnetic
Resonance Environment. ASTM International, 100 Barr Harbor Drive, PO
Box C700, West Conshohocken, Pennsylvania.
Non-clinical testing demonstrated that the On-X Conform-X Mitral Heart
Valve Prosthesis, Size 25-33, is MR Conditional. A patient with this device
can be scanned safely immediately after placement under the following
conditions:
Static Magnetic Field
• Static magnetic field of 3-Tesla or less
• Maximum spatial gradient magnetic field of 720-Gauss/cm or less
MRI-Related Heating
In non-clinical testing, the On-X Prosthetic Heart Valve, Conform-X Mitral
Heart Valve Prosthesis, Size 25-33, produced the following temperature
rise during MRI performed for 15-min of scanning (i.e., per pulse sequence)
in the 3-Tesla (3-Tesla/128-MHz, Excite, HDx, Software 14X.M5, General
Electric Healthcare, Milwaukee, WI) MR system:
Highest temperature change +1.6˚C
Therefore, the MRI-related heating experiments for the On-X Conform-X
Mitral Heart Valve Prosthesis, Size 25-33, at 3-Tesla, using a transmit/receive
RF body coil at an MR system reported whole body averaged SAR of 2.9-W/
kg (i.e., associated with a calorimetry measured whole body averaged value
of 2.7-W/kg), indicated that the greatest amount of heating that occurred in
association with these specific conditions was equal to or less than +1.6˚C.
Artifact Information
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 On-X Conform-X Mitral
Heart Valve Prosthesis, Size 25-33. Therefore, optimization of MR imaging
parameters to compensate for the presence of this device may be neces-
sary.
Pulse Sequence T1-SE T1-SE GRE GRE
Signal Void Size 1,090-mm
2
686-mm
2
1,478-mm
2
1,014-mm
2
Plane Orientation Parallel Perpendicular Parallel Perpendicular
*The MRI findings apply to this specific largest heart valve prosthesis and all
other smaller sizes which are made from similar materials.