Why MRI is Important:
Magnetic Resonance Imaging, or MRI, is one of the most important tools of modern medicine. MRIs can be used to evaluate almost every kind of medical issue, from brain tumors to twisted ankles. They provide clear images, and in some instances, also provide superior visualization. Because they do not expose the imaging subject to radiation, they are generally preferred over CT scans, even when the two scans would reveal the same information.
MRI in HCM:
In the last several years, MRI has also become an important tool in the evaluation of hypertrophic cardiomyopathy (HCM). The images resulting from MRI have proven superior in visualizing the size and structure of the heart and, when used with a contrast agent, MRIs are able to show the extent of scarring in the HCM heart.
MRI Hasn’t Been an Option for Many of Us:
MRI has been unavailable to those of us who have an implantable defibrillator or ICD to in order to protect us from sudden cardiac arrest. Until recently, having an ICD was an absolute contraindication to MRI. Newer MRI-safe ICD systems have been in use for the last few years, but that still leaves in place the contraindication for those of us who have older ICD units in place. That problem is that older lead systems that were implanted along with old, non-MR compatible generators may be incompatible with the newer MR compatible technology, and it may not be possible to simply hook up these old leads to a new MRI compatible generator. And, it is not as easy as you might think to extract old leads. Scar tissue grows around these leads, making their removal an intricate and dangerous procedure that is best done only in carefully controlled circumstances by highly specialized physicians.
All of the above factors made my own personal situation particularly complicated. My story is as follows:
My Brain Tumor:
Fifteen years ago, I was diagnosed with a benign brain tumor known as an acoustic neuroma (AN). Nothing I have been through in my life has come close to the fear and anxiety provoked by that diagnosis and its ensuing treatment, which was why I was particularly concerned when, last July, I was experiencing a mild sensation of vertigo. As it happened, it had also been more than five years since I had last had a brain scan, and I was overdue.
Could My Symptoms Mean Regrowth?
My vertigo could have indicated anything from a tumor regrowth to a leftover deficit resulting from my original tumor and its removal—or something completely unrelated. In order to figure out the cause, I first had to get a brain scan.
CT Scans Instead of the Usual MRIs Due to ICD
For a person who has had an AN, the normal protocol is to get sequential MRIs in the years following surgery to ensure there have not been any recurrences. Though I had several MRIs in the first year following my AN surgery, I had to switch to CT scans after about a year because that was when I was implanted with an ICD, due to several risk factors for sudden cardiac arrest presented by my HCM.
I knew when I got my ICD that my new implant meant that I would, from then on, be unable to receive MRI scans. Instead, I would have to undergo CT scans, which all my doctors acknowledged were not as good at finding ANs, and which would expose me to radiation. Nevertheless, my cardiologist and electrophysiologist felt that the cardiac device was necessary, and my neurosurgeon felt that the CT scan would be an adequate substitute, given the circumstances. So, every few years since implantation of the ICD, I had gone in for a CT scan, and so far, all of them had been negative.
Scientific Developments Re: ICDs and MRI
Meanwhile, over the past 14 years, I’ve kept a close watch on scientific developments related to ICDs and MRIs. I took note that Johns Hopkins in Baltimore, MD had created a special protocol for performing MRIs on patients who had ICDs. With great interest, I read how Medtronic, the manufacturer of my device, had developed ICDs and leads which were certified safe for MRI use and which allowed patients implanted with them to undergo MRI. I read the results from the Magna-Safe registry and trials, which studied the safety of MRIs in patients with non-MR compatible ICDs who had undergone MRIs anyway.
Then, in early 2016, I opened my mailbox to find a circular in the mail from UCLA which advertised it as the first hospital in the Western U.S. doing routine MRIs for patients with pacemakers and ICDs without MR compatible devices. “Finally!” I thought. It seemed that the possibility of getting an actual MRI instead of a CT was now a real possibility.
Could I get a MRI With My Old Device?
I decided to investigate what would be necessary in order for me to obtain a MRI at UCLA with my current device and leads. I learned from speaking to the UCLA staff that that my neurologist’s orders for the scan would have to be written in such a way that made it clear that a CT scan would NOT be an adequate substitute for an MRI. I would have to be supervised during the entire scan, which would be done pursuant to a specifically tailored protocol, and, of course, UCLA would first have to determine that I was an appropriate candidate for the scan. Two disqualifiers were being pacemaker dependent and having abandoned leads inside my body. Neither situation applied to me.
Would Insurance Pay for a MRI?
It appeared to me that I was a suitable candidate, so the next step was to investigate whether my health insurance policy would even pay for this scan. Since the scan would not be FDA approved, I learned that I could be facing an uphill battle to obtain coverage. Though I was never able to obtain a definitive answer about coverage, I did know that I did not wish to be left holding the bill for an expensive scan without insurance coverage.
My next step was to call my electrophysiologist to see what he thought. He told me that he had not yet sent a patient with a non-MR approved device for a MRI scan, and was thus reluctant to do so unless absolutely necessary. However, he and I also discussed the possibility that my current ICD might soon be replaced with a MRI compatible generator, which was now readily available. The problem still however remained that one of my leads was not approved for MR use. It was after this discussion that I decided to investigate how and if my ICD could ever be made MR-compatible.
Can I Become MRI Compatible?
I knew from a previous discussion with a Medtronic rep during a routine interrogation in early 2016 that one of my two currently implanted leads (my pacing lead) was already FDA approved for MRI. Then, through a discussion with an acquaintance at Medtronic in August, I learned that the company was in the process of seeking FDA approval to have more existing leads retroactively approved as MRI safe. Lo and behold: my defibrillating lead was one of the leads included in this group!
Excitedly, I reached out to others at Medtronic to find out how long the approval process was expected to take. I was delighted to learn that they hoped to have approval very soon.
For years, I operated under the mistaken impression that some metallic material in the leads made them unsuitable for MRI scanning. I’ve now learned that this was not the case. Instead, the problem was only that federal regulators had never deemed the leads safe for MRI scanning, even though, technically, the leads are made of materials which are fully compatible with MRI scans.
Finally, an Answer!
Through my contacts at Medtronic, I was put in touch with a member of Medtronic’s Cardiovascular Public Relations group who was finally able to provide the clarity I needed just last week. I am now thrilled to tell you that both of my leads: 5076 – 52 and 6947 – 65 are, as of last week, MRI compatible.
When my current device, a Medtronic Protecta XT DR, is due for replacement in approximately 2 years, I will have it replaced with a new MR compatible generator, and then, I will be free to undergo MRI exams at any facility in the US.
[NOTE – My situation is different from those who were implanted in the past few years with a “Sure Scan” MRI compatible system. The below only applies to those implanted with older devices.]
How You Can Find Out if Your MEDTRONIC Leads are MRI Compatible!
However, if you are like me, and have an older system, you will have to ascertain whether your old leads have been retroactively deemed approved as compatible with MRI safe generators.
You can check the status of your leads by using this link together with your patient card which lists the model numbers of your device and leads, along with the lead lengths and the serial numbers of the devices (my serial numbers are covered up for privacy).
The catch is that you will have to select a MR safe generator from the drop down menu, which you probably do not know at this point. I chose the Evera XT DR device from the drop-down menu which is the most like my current device and is compatible with my current lead system.
When I select this device from the drop-down menu, I am able to see that along with my current leads, the new system would be MR compatible.
- Select your country and language:
2. Look at your card to see which model and length of leads you have:
3. Select the device model you will be getting as a replacement for your current generator, along with your current leads and length from the drop down:
4. Voila! You will see if your leads are MRI Compatible. Look for the little yellow triangles for confirmation.
I also learned from Medtronic that once implanted with a new MR compatible device, a patient will receive a NEW card from Patient Services which will state that the patient has a MRI compatible device.
I hope that relating my experience will help clarify matters for all of the other patients out there implanted with older pacemaker and ICD models.
Oh, and in case you are wondering about what happened to me and my fear of a AN regrowth, I decided to have a CT scan and it was thankfully negative. Within a few weeks, my dizziness cleared up. And when I am due for another scan in another 4 years, I plan to have an MRI!