iMRI: bridging research and reality

Episode Transcript

Recorded live from the Cook booth at SIR and featuring leading experts in the field of interventional radiology discussing a wide range of IR-related topics, this is the Cook@ SIR Podcast Series.

Good afternoon. We’re coming to you from SIR, and today we’re going to be talking about interventional MRI, what you might want to know about advances in this space, and some thoughts about how this could benefit the IR community and your patients in the years to come. Today, I’ve got with me Dr. John Kaufman and Dr. Kavi Krishnasamy.

Hey, Joshua. Glad to be here, and we’re all kind of friends, so we’ll be first-name basis from here on in.

Thank you.

I’m the chief medical officer for Cook and a practicing interventional radiologist, and just super excited to be talking about this.

Fantastic, and Kavi?

Yeah, thank you, Joshua, for having me here, and it’s an honor to be here with both of you. I’m an interventional radiologist, interventional oncologist at University of Alabama Birmingham.

Fantastic. Really excited to be discussing this today. Today, we’re going to go over what is iMRI, and what is the promise it has for the clinical space, talk a little bit about some of the history here, the current state of some of the research that we’re doing, some challenges that are yet to be solved, and then talk about what this looks like in the future, the kinds of procedures that we’re looking at and where we see this technology growing in the future. So, I wonder maybe if we could start with just a general overview of what is interventional MRI. And Kavi, I might hand this to you first. I think you first encountered this in your time at Emory. As you were there, what was IMRI, and what would you want folks to know about it if they’re not aware of this space right now?

Yeah, it’s a great question. I think it’s a little bit of a challenging one to answer as well. For me, in my practice, when I go back to my first five or six years of practice, I was at the NIH. I didn’t have access to Y90, so I learned very early to be a “ablationist,” and when I went to Emory, which was kind of my second job, one of my roles was to kind of build the ablation program. There is a deficiency in terms of what we can offer with just CT and ultrasound, and there are times when we’re just guessing to really get a conformal ablation run at tumor. That’s where iMRI comes in, and it was not uncommon for me to refer to my iMRI colleague, who was Sherif Nour at Emory, for lesions that I couldn’t see or couldn’t target for whatever reason. He had capability in iMRI that I did not have in CT and ultrasound.

Fantastic, and John, as you’ve kind of been around this space, as you’ve been around some of the research that’s happening in Cook, what are some of the advantages? Intervention within the bore of an MRI, what are some of the advantages that you’ve seen with the MR visualization that meet some of the clinical challenges that you’ve got today?

Yeah, Joshua, one of the most important things that, as the diagnostic world knows very well with MRI, you can see many different things that you can’t see with CT or ultrasound. People have been trying to do this for a long time, and we’ll talk about why we seem to be really gaining ground now, but our goal is to expand the number of patients or the number of conditions that make the point of intervention earlier than it has been. We’re not thinking that, “Wow, this is just going to empty out the CT scanners or empty out the ultrasound machines.” We all know that there are so many patients that need to be treated, but if we can now start providing treatments for things that, in the past, we could see in MR, but then really couldn’t make any kind of intervention in that environment, I think we’re going to just add to the overall care of patients.

Yeah, absolutely. I think maybe looking at just the MRI piece of that, something that I think about, a framework that I think about, is spatial, temporal, and contrast resolution, and each of these different image modes has them, fluoro being high spatial, high temporal, lower soft tissue contrast. CT being higher soft tissue contrast, little bit lower temporal, although you can do CT fluoro. And then, MR being really a little bit of a Choose Your Own Adventure®, with the ability to run high temporal at the expense of spatial and contrast. We’ve seen 10 frames a second. I’ve seen on research systems even higher than that, but then the ability to get the super high-quality diagnostic images that you’re both seeing clinically. I wonder, if we take those as kind of a framework there, where, in each of your practices, the ability to choose that mix of spatial, temporal, and contrast would be of real advantage. I know that, Kavi, you’re doing a lot of tumor ablation. I wonder just contrast against CT versus MR, one of those times where you’re navigating by landmarks, what are you trying to see better, and where does that MRI offer some promise there?

Yeah, absolutely. I think when you frame that question from the capabilities of different modalities, if something is ultrasound-visible, that makes things a lot easier, especially in a moving target like the liver, as an example. Obviously, you can’t use ultrasound in the lung, but very relevant in the liver and the kidney. I think it becomes a little bit more challenging in CT with CT alone. It’s interesting that I was having this conversation recently with a colleague. I do feel like ultrasound skills in our trainees and our fellows are starting to diminish. Less and less people are using ultrasound as a primary modality, so then when you turn to CT alone, you lack that contrast resolution, don’t have the ability to see small lesions, potentially. You have a moving target in CT that you’re trying to compensate for the motion in some capacity, and then you have needles that are shadowing out small lesions as well, so there are a lot of drawbacks to a CT-only system or when the lesion is invisible in ultrasound. And so then, how do you attack those lesions to ablate them? That becomes very challenging. I do not believe in just ablating based on landmarks. I think there’s a better way to do it. I very commonly use ablation confirmation in those settings. Give contrast pre, give contrast post. Make sure I’m getting the ablation zone that I need. But again, is there a better way to do that, and I think that’s where iMRI comes in.

I wonder, John, if you would be able to speak to, as you’ve looked at this space, that impact of moving to a mode without radiation, how you think about that and how you think about that across the spectrum of physicians that are out there practicing today and their interaction with that?

Yeah, I think radiation exposure is something everyone is fortunately thinking more about. In the past, probably particularly some of the more senior or expert-level people have been a little bit cavalier, but I think there’s a healthy concern now and focus on that. Clearly with MR, there’s no radiation, so you are both providing a procedure for a patient without exposing them to radiation, and maybe more important because the operator is doing this on a regular basis with frequent exposures, you’re not getting the scatter or any of the direct radiation. One of the big advantages I see with MR compared to ultrasound, which is the obvious non-radiation alternative, is the ability to have multiplanar imaging. You were talking about spatial, very hard to do with ultrasound currently. There may developments in ultrasound where we have the ability to intervene and visualize in multiple planes, but not sort of routinely at this point. So that’s a huge advantage that I would see in MRI in addition to some of the things that Kavi had talked about. No lead, right? So if you have no radiation, there’s no lead, so that actually is not a radiation issue; it’s an ergonomics and workplace injury, chronic injury kind of issue, and that becomes an advantage. Probably there will be other things that we have to think about if you’re working in a magnet all the time. There may be other kind of things you have to consider, thinking about where you place monitors and other of your support systems so that you’re not negating the benefit of not wearing lead by having to turn yourself into a pretzel. I think a lot of this speaks to, is not–as we will probably talk about–not just being a one device that we suddenly will start using, but thinking about it in a holistic way.

I think that’s a great segue, and I absolutely want to get into that workflow and what this looks like in a complete way, but I wonder if we might touch on first some of the impressions that you’ve heard from colleagues or that you’ve had yourselves as to why this hasn’t blossomed in the last 20 years. I mean, Cook made needles for this space starting, I believe, in 1996, so this is a space that we’ve been aware of. We’ve had ultrasound, CT, fluoro, MRI as imaging modes for a while now, but this hasn’t taken off in the interventional space. There are some people who have this at their sites and it’s been a really Herculean effort to get it off the ground. So what have been the challenges? Why hasn’t this become ubiquitous yet? John, I might start with you.

Oh, I was going to let Kavi answer that, but I’m happy to do that. It’s been around for a while, and I think some of the reactions we will get from individuals who have been around for a while is, “Oh yeah, I tried that 21 years ago,” or “I’ve already done that, but I just didn’t see any future in it.” And the question is, why was there no future? It becomes partly choosing the right therapeutic or clinical targets, and if you go for something that’s maybe just a little bit unrealistic, you’ll get frustrated pretty quickly. Another is that having just a needle or a magnet is probably not enough. One of the things that I have seen that’s really most exciting to me is that this is a collaboration between the equipment manufacturer–the heavy equipment manufacturer is Siemens–and Cook. Rather than approaching this from “Let’s make a device that can be used in a magnet and see where people take it,” it’s been “Hey, how can we work together to optimize the tools to fit the imaging modality and plus that whole environment?” I think that’s new. We don’t do that with angiomachines. We don’t do that with CT scanners. We don’t do that with ultrasound machines. So that’s a really exciting part of this. That’s, I think, very novel.

Absolutely. Kavi, anything you want to add to that?

Yeah, it’s a great question, and to echo what you said, John, even today when I talk to people about interventional MRI, those are the kind of consensus statements, even today. Obviously, again, there’s a gap with just CT and ultrasound for percutaneous interventions that’s not being filled. I get innovation and change are sometimes difficult to wrap our heads around and understand where that fit and utilization will be. Also understand that completely, but I look back at my career and especially my time at Emory–this was 2019, and even at that time, iMRI was necessary but not considered economically viable, and then you add in the device constraints that we had as well. Now we’re coming full circle with the opportunity to have a system that is more economically viable, that has a portfolio of devices that we can utilize, and then the downstream benefits, which I know we’re going to get into, are tremendous, and so for those of us that value the percutaneous space and understand the gaps with what the current technologies are, this is limitless possibility in this form.

It has been just an incredible space, for my part, to be a part of on the research side, on the Cook Medical side, and just so that everyone is aware, we have talked about this in a limited fashion before, but Cook has a research partnership with Siemens Healthineers. We’ve got a research suite that we’ve built really to explore together what the interventional MRI space could look like. As we spoke with physicians and as we spoke with other companies, what we found is that physicians were working with the imaging companies; physicians were working with the device companies; sometimes physicians were taking it upon themselves and working with the research organizations in their university hospitals to create devices. Something that Cook did is work with Siemens to bridge that gap between the two companies, the one that probably had the most lawyers involved and the most time to hammer out. To be able to come together and really look at this and say, as device manufacturers, as imaging manufacturers, as physicians in the clinical space, “How do we work together on this to really have it be different this time around, to have there be devices for this space?” We are going to talk about some devices in this. I will just put the caveat out there: There are no commercial devices that we have in this space at this time. Everything we talk about will be prototype devices in a preclinical setting.

There has been a desire to really look at this space with new eyes and understand what can be with low-field magnets that open up new possibilities for device manufacturers and for device usage, that devices that feel the way the device in an angio suite or a CT would feel. As you’ve gotten to interact with that and those in our research suite, I wonder what some of your first impressions have been about this new time around. Kavi, I know that you’ve been able to join us here quite recently. What were some of those impressions from your side?

Yeah, it’s a great question. I think, one, having done a lot of CT interventions, realizing that what we call CT fluoroscopy is not actually live fluoroscopy; it’s step-and-shoot, effectively. And MR in this iteration is live MR fluoroscopy, so that was very eye-opening to see for the first time, that I could direct a needle, compensate for motion like I can with ultrasound, but in multiple dimensions, and hit a target live. The skill set for me translated very well from CT to MR. That made it very easy, the nuance and the difference being that I’m controlling less tableside and I have somebody outside the room helping me facilitate the actual intervention, so similar in some ways, different in some ways, but exciting nonetheless.

Absolutely.

Yeah, I think one of the great advances here is the tools and the marriage of the tools with the imaging modality, and when Kavi’s talking about advancing a needle to a target live, it’s not something with this gigantic blooming artifact that you can’t really tell, “Am I there? Where’s the tip?” The images are really striking in sort of their definition of the tools, and that’s been a real challenge. It just opens your mind to all sorts of other possibilities. It’s getting to things that are in tough places that are moving, but you can just watch yourself go into multiple planes. The experience I had in doing this was then injecting something and watching something diffuse under MR and seeing really where it goes. It’s often surprising how it’s different in reality from what you think is happening. The picture you build in your mind, “I’m injecting; it must be doing this,” and you’re injecting into tissue and it’s doing something very different, but all of a sudden you can see, “Ah, we can use that in so many different ways.” One, being able to see things like that to understanding what’s happening. I think it’s like any other thing. When you give an interventionalist a new tool, all of a sudden the wheels start turning. “What can I do? Where can I-

Absolutely.

… “use this? What else? What couldn’t I do yesterday that now, if I’d had this, I could have done it?”

Absolutely, absolutely. Well, and I’ll piggyback on that, John, and I’ll say I’m one of those people that if I have an anterior segment 8 lesion and I send them for an ultrasound and the ultrasound can’t find the lesion, I’m still going to ultrasound myself because maybe 50% of the time I can find the lesion, but then that other 50% of the time, what do I do? And that’s where this solution comes into play.

You know, Kavi, I think part of that is, you know what you’re looking for, you have a mental image of where it should be, you’ve probably studied the cross-sectional imaging to figure out, so you can push it maybe a little more–

Yep.

…whereas, with this modality, all that stuff leading up to having to find it is not going to be an issue.

That’s a great point.

You’ll be in the modality that showed you this subtle lesion actually for your intervention.

Yeah. Well, and that’s what opens it up, I think, to the broader community as well, and so then it doesn’t become as challenging of an ablation replacement in a vertical direction, and everybody can do it, and that’s exciting.

Yeah, I think a term that we think about is democratizing certain things. I think it’s okay to bring it up in this context–

Of course,

… but the idea that you can make, just as you said, a procedure that might take you to do because no one else really has the ability to get to it, that now most people can do if they just have these tools.

Yeah.

I wonder if maybe, piggybacking on that–I know that, Kavi, we’ve done a little bit of work just collecting some early data with you around kind of, what does that learning curve look like? Not to get into all of the data part of that, but anecdotally, what are you seeing with this? I mean, both your experience coming into the magnet for the first time–I think the first day we had a pre-clinical day, we gave you some fun challenging things up in the dome of the liver–but then also as you think about trainees coming through, what does that look like compared to CT, compared to ultrasound-

Sure.

… as far as precision needle guidance goes?

It is a little bit of a black box if you’ve never done it, which—

Oh, absolutely.

… was the exact situation that I was in, but surprisingly, very easy to adapt to, and those skills very much translate between CT and ultrasound, so I didn’t find it very challenging. Again, the unknown to me was, now I’m relying on somebody else to manipulate the sequences and images for me that’s sitting outside at the station. That’s the kind of one nuance that was very different, but an easy adaptation. Much easier than I thought, actually. I thought I would struggle a little bit–or a lot–and it actually went fairly seamlessly. John, how was your experience?

Well, I was actually going to ask Joshua if he could talk about some of the challenges around communication. There’s a lot of thought going into how everyone in the suite will interact with each other and outside the room. I don’t know if you can talk a little bit about some of the challenges and potential solutions.

Absolutely. I’m really happy to. As we started working in the machine, as we started bringing physicians in to work in the machine and the procedures got a little bit more complex, one of the things that you have to remember is you’re not working in full thicknesses, you’re working in slices. Not only do you have to visualize your target, you do a high-res planning scan, you understand where you want to go, the trajectory. As you’re advancing a device, though, you need to be in that plane. There’s sometimes breathing motion, and the plane that you are in is being controlled by someone outside the room, and there aren’t very many solutions right now for being able to talk in both directions with the technologist outside if you’re the physician at tableside. And so what we realized very quickly is, communication was going to be absolutely critical to any sort of future success of this. And as we get more and more people in the room–you know, shifting over to something like a more complex vascular procedure down the road—you have to have the ability for four, five, six people to be able to communicate very clearly across themselves and to that technician outside who is giving you the images that you need to be able to do your work. Additionally, from a technical perspective, that MR space is a harsh environment to design for, particularly with something like radio communications when you’re inside of a Faraday cage.

We have found a couple of groups, one in particular, that are working in this space and moving to advanced technologies that will allow very clear communication, in addition to then allowing for hearing protection because the magnet is also a loud environment. The 0.55 Tesla is a little bit quieter, not as loud as a 1.5, not as loud as a 3.0, but being able to have good hearing protection and then good communication between all of those groups to make sure you are seeing the images that you need to guide a device down to a target has been truly a critical part of this.

I will add to that and say that I wish I had that in CT, because most of my communication in the CT scanner is hand signals, and at times maybe even smoke signals—no, I’m kidding, not smoke signals—but hand signals through a window to try to get communication of what I need across, and that obviously makes a huge difference in this type of communication.

Yeah, absolutely. I’m wondering if you could also speak to—just on that, coming back to that training piece, as you think about training young attendings, as you think about training fellows, how you see this fitting in and what that training would look like, maybe with a comparison to CT or ultrasound. Maybe John?

I think part of this will be figuring out where we want to use it, and probably each institution is going to have a different place that they’re going to want to fit in the iMRI, so understanding where your clinical use is going to be is going to be very important to figure out your training. This is, as you’ve kind of suggested, a team-based sport, very much, that you need to have a lot of people involved in the system and the processes and the workflows, so the training will probably not just be the residents, but it’ll be the rest of the group as well.

Understanding within whatever clinical context you are most frequently going to be working, where you want your CT, where you want your ultrasound, where you want your MRI, I think those will all be things that we can work on, and each institution will be a little different, but it will be very important to integrate this into the resident training early on, that this isn’t just a thing that, “Oh, this attending goes off and disappears and does these procedures and no one else really knows what’s going on,” but really get it involved in the daily workflow, the daily case conference, the case selection, clinic discussions, things like that.

I think we might have had a little bit of a change of plans, and I’m getting some signals from outside the glass that we’ve got about two minutes before this space is getting shut down.

Okay.

What I might say is we’ve not talked about challenges, we’ve not talked about some of what comes next. I wonder if there’s one thing that each of you would want the broader community to be aware of about this, what would that be? Kavi, I’ll start with you.

Yeah, I think if you ask me the one thing I’m most excited about right at this moment, it is this is a technology that can legitimately allow us to clear a liver of multiple metastases more accurately than I think CT and ultrasound can. When you look back at the CLoCK study—it referenced the CLoCK study a lot—when you look back at the CLoCK study and they clear the liver, outcomes were significantly better. Doing that with just CT and 15 sub-one-centimeter or -two-centimeter lesions is going to be very challenging. Doing that in MR is very possible, and the ability to live visualize your ablation zone and thermal map and get confirmation in real time—not post, but in real time—that is Holy Grail to me.

This is something that gives us real-time visualization in a way that we’ve only had an ultrasound, but in multiplanar with best-in-class tissue visualization without radiation.

Yeah, I think what—I put my Cook hat on for this, to answer this question—I think it’s really important for everyone to understand that Cook and Siemens are in this for the long term, that both share a very deep commitment to advancing care for better patient outcomes, and we see that this is one of the ways to do that. We’ve been at this seven years?

Mm-hmm.

Is that right?

Yep.

So this is not just something we got interested in six months ago, a year ago. This has been a long-term investment and it’s going to continue long term. We just hope it’s going to continue to grow, that we’ll find more places to apply this, get better patient outcomes, increase the number of patients we can treat, so we’re in it for the long term.

Absolutely. And as we wrap up, I would say this is an area we’re really excited about. This is an area, a partnership, that we’re genuinely excited about, being able to not only bring devices but world-class imaging and an integration between the two. We’d love to chat with you. If you are interested in this, please reach out. imri.questions@cookmedical.com is a great way, or reach out through your local rep. Thank you so much.

Yeah.

Sorry for the truncated—

I think we’d better—

… truncated podcast.

… we’d better get going—

Thank you so much.

… before we quench.

Yeah.

That’s a good one. I like that one.

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