Guidelines for the Management of Patients with Vascular Access Ports
Referred for MRI Examinations*

Frank G. Shellock, Ph.D., FACR, FISMRM, FACC

Adjunct Clinical Professor of Radiology and Medicine
Keck School of Medicine, University of Southern California

Director of MRI Safety
USC Stevens Neuroimaging and Informatics Institute

University of Southern California
www.MRIsafety.com

In the clinical magnetic resonance imaging (MRI) setting, it is often necessary to manage patients with vascular access ports (1-6). MRI labeling information exists for numerous vascular access ports. By following the MRI labeling information (i.e., presented in the Instructions for Use, the Patient Identification Card, etc.), patients with vascular access ports have safely undergone MRI examinations, including those performed using MR systems operating at 3-Tesla (1-6). Notably, there has never been an adverse event reported in association with performing MRI in patients with these implants.

Unfortunately, the standard policy that MRI labeling information is required before allowing the use of MRI in patients with vascular access ports limits access to this important diagnostic imaging modality for those patients for which labeling information is unavailable. In consideration of the relevant peer-reviewed literature and other related information (1-6), it is acceptable and safe to perform MRI examinations in patients with all vascular access ports by following specific guidelines developed by taking into consideration the primary safety concerns (i.e., magnetic field interactions and MRI-related heating) for these implants.

By adhering to these conservative MRI conditions, patients with vascular access ports can benefit from the diagnostic imaging information provided by this important noninvasive imaging modality.

Guidelines. A patient with a vascular access port may undergo MRI using the following guidelines:

• 3-Tesla or less
   
• No restriction for the spatial gradient magnetic field
   
• Whole body averaged specific absorption rate (SAR) of 2-W/kg (i.e., operating in the Normal Operating Mode for the MR system)
   
• Maximum imaging time, 15 minutes per pulse sequence (multiple pulse sequences per patient are allowed)
   

*Important Note: The “Guidelines for the Management of Patients with Vascular Access Ports Referred for MRI Examinations” should only be implemented for use after the careful review by the supervising radiologist or other physician responsible for the MRI facility and with the adoption of the information as a written policy.

Important Note: Any deviation from the above MRI conditions requires prior approval by the supervising physician.

Important Note: These guidelines must be reviewed on an annual basis to confirm that no new vascular access port has become available that substantially deviates from the above MRI conditions or that is labeled, MR Unsafe.

References
(1) Shellock FG. Biomedical implants and devices: Assessment of magnetic field interactions with a 3.0-Tesla MR system. J Magn Reson Imag 2002;16:721-732.

(2) Shellock FG, Nogueira M, Morisoli S. MR imaging and vascular access ports: Ex vivo evaluation of ferromagnetism, heating, and artifacts at 1.5-T. J Magn Reson Imag 1995;4:481-484.

(3) Shellock FG, Shellock VJ. Vascular access ports and catheters tested for ferromagnetism, heating, and artifacts associated with MR imaging. Magnetic Resonance Imaging 1996;14:443-447.

(4) Titterington B, Shellock FG. Evaluation of MRI issues for an access port with a radiofrequency identification (RFID) tag. Magnetic Resonance Imaging 2013;31:1439-44.

(5) Shellock FG. Reference Manual for Magnetic Resonance Safety, Implants, and Devices: 2020 Edition. Biomedical Research Publishing Group, Los Angeles, CA, 2020.

(6) www.mrisafety.com

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