Implant Approval Guidelines
Steps to getting an Implant approved
Most TMS protocols, when implemented properly, are considered minimal risk activities. However, because many TMS protocols exist, each protocol must undergo its own individual safety analysis with TMS Lab personnel. In addition, in order to minimize risk, only properly trained and certified TMS personnel are allowed to administer TMS to human subjects. This certification includes practical training on use of TMS, formal safety training and training as a first-responder in case of an emergency.
TMS Protocols
Many TMS protocols exist and the TMS Lab personnel should be involved in the design and implementation of TMS studies in the lab. The most common protocols in use are single-pulse TMS, paired-pulse TMS, low-frequency repetitive TMS, high-frequency repetitive TMS, and theta-burst TMS. Each protocol is defined by a combination of TMS intensity, frequency, duration of stimulation, and pattern of stimulation (continuous vs intermittent stimulation).
In general, higher intensities, higher frequencies, and longer durations of stimulation carry higher risk. All procotols currently in use are done within limits of safety guidelines first established in 1998 (Wassermann 1998; see Table 1). These guidelines have been reaffirmed by the recent publication of a comprehensive and consensus review of TMS safety, ethics, and application in research (Rossi et al 2009) which essentially incorporates and supercedes the Wassermann 1998 article. Table 4 in the review article reproduces this table. The Rossi et al 2009 safety article is required reading for anyone who wishes to use TMS in a research study.
Standard TMS risks and exclusions:
Standard risks disclosed in all TMS studies in our lab (see specific IRB for details):
- headaches, neck aches
- hearing threshold shifts
- heating of metal on the scalp/head
- syncope (fainting)
- accidental seizures (very rare)
- unforeseen potential events in research protocols
General exclusion criteria (see specific IRB for details)
- age >= 18 years old
· metals in head (except dental fillings)
. history of seizures or 1st degree relative with history of seizures
. medications that lower seizure threshold
· a serious or active medical, neurological, or psychiatric illness
· pregnancy
Please consult with TMS Lab personnel if you have any questions.
Readings:
Rossi, S., M. Hallett, et al. (2009). "Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research." Clin Neurophysiol 120(12): 2008-2039.
Wassermann, E. M. (1998). "Risk and safety of repetitive transcranial magnetic stimulation: report and suggested guidelines from the International Workshop on the Safety of Repetitive Transcranial Magnetic Stimulation, June 5-7, 1996." Electroencephalogr Clin Neurophysiol 108(1): 1-16.
TMS Safety Training
For information on safety training please contact TMS Lab personnel
Only Dr. Roger Woods can approve the safety of an implant for subjects being scanned at the BMC.
‐ A subjects personal physician cannot approve the safety of an implant.
‐ A PI of a study cannot approve the safety of an implant.
‐ Just because a subject tells you that they have been scanned with this implant previously does not mean you can skip the approval process.
‐ Note: implant approvals are only valid for 6 months. For longitudinal studies, you must resubmit your implant request to Dr. Woods if your initial approval has expired.
‐ The approval process takes time and is not instantaneous. You should expect a reply in 24-48 hours. Therefore, you should have your subjects fill out the metal screening form as far in advance as possible to eliminate delays on the day of the scan or the possibility of having to cancel a scan due to an unapproved implant.
The researcher then goes over the form to check if the subject has indicated there is an implant.
If they do not have the information, have them contact their physician to get the details.
Information required:
‐ Type of implant (ie IUD, pacemaker, surgical clip, etc)
‐ Manufacturer
‐ Model #
‐ Material
‐ Date implanted
Once you have all the details of the implant, you must then research if the implant is safe for scanning on our 3T MRI scanner. You can do this two ways:
Go to MRISafety.com
‐ Search for the implant in their database.
‐ If MRISafety.com states it is "Safe" or "Conditional", you can proceed with the approval process. If they state the implant is "Not Safe" for scanning on a 3T system, the subject is not allowed to be scanned at the BMC and there is no need to contact Dr. Woods.
Contact the manufacturer of the implant
‐ Simply Google the manufacturers name and/or, place a call to get documentation stating the implant is safe for scanning on a 3T MRI scanner. It is always best to get a hard copy for your records.
‐ If the manufacturer states it is "Safe" or "Conditional," you can proceed with the approval process. If they state the implant is "NOT SAFE" or has "NOT BEEN TESTED" for scanning on a 3T system, the subject is not allowed to be scanned at the BMC and there is no need to contact Dr. Woods.
You may come across an Implant that is designated as "Conditional" in MRISafety.com or from the manufacturers documentation.
For Conditional 5 Implants, you MUST find documented research that includes the necessary safety conditions of the implant before contacting Dr. Woods.
Here is an example of what you should look for:
‐ Static magnetic field of 3 Tesla or less
‐ Maximum spatial gradient magnetic field of "#"-Gauss/cm or less
‐ Maximum MR system reported whole-body-averaged specific absorption rate (SAR) of "#"-W/kg for 15 minutes of scanning (per pulse sequence)
These types of implants can be safe to scan at 3 Tesla BUT they routinely require that a BMC technologist (or staff member) is present during the entire scan to monitor the SAR level and ensure implant safety.
Dr. Woods will alert you when a BMC technologist is required to be in attendance and will assign you an ISMA #. You should then look for a time-slot during regular daytime
tech hours and then contact the BMC techs at
BMCtechs@mednet.ucla.edu. Let them know the date, time, ISMA #, details of the conditional scan and ask if they can attend the scan to monitor the conditional implant. If a BMC tech cannot staff that scan then you must reschedule until a later date/time when they can be present.
After you've researched that the implant is safe for scanning on a 3T MRI scanner, email
Dr. Woods at: rwoods@mednet.ucla.edu for approval. You must include the Implant safety documentation in this email.
Note: implant approvals are only valid for 6 months. For longitudinal studies, you must resubmit your implant request to Dr. Woods if your initial approval has expired.
