Prostate MRI Explained: A Patient’s Guide

Phillip Koo, MD [00:00:00] This is Philip Koo from the Prostate Cancer Foundation, and welcome to a special webinar that we have talking today about prostate MRI. And we’re joined by Dr. Andrei Purysko, who’s a radiologist at the Cleveland Clinic in Cleveland, Ohio, who is an expert and oversees the ACR committee that looks at the quality of prostate MRI for accredited centers throughout the United States. So, Andrei, thank you very much for joining us. 
 
Andrei Purysko, MD [00:00:26] Thank you for inviting me. It’s my pleasure. 
 
Phillip Koo, MD [00:00:29] So, prostate MRI really is something that’s grown in volume over the past several years. And for those who’ve had a diagnosis of cancer or suspicion of cancer, they’ve probably had one on themselves. But before we sort of get into the details, tell us a little bit about what is MRI and then what is prostate MRI. 
 
Andrei Purysko, MD [00:00:49] Yeah, so MRI are basically very sophisticated machines that have very strong magnets and use radio waves to create very detailed images of what’s inside of our body. In this case, a prostate MRI, we look not just at the prostate itself, but surrounding structures, and we can actually see the cancer and how it’s behaving on a man. 
 
Phillip Koo, MD [00:01:11] Great, so for prostate MRI, there’s often discussions about sometimes you need a coil, like an endorectal coil, so a device put up through the rectum to help image the prostate. Some places don’t. Can you help dispel the myths around that endorectal coil? 
 
Andrei Purysko, MD [00:01:31] Sure, absolutely. And the first prostate MRIs initially were done without endorectal coil, but the magnets were not as powerful back in the day. This is in the 1980s. Eventually, the MRI evolved, and we have much more powerful magnets nowadays that we don’t need to use the endorectal coil. The endorectal coil was basically an antenna that was placed close to the prostate so we could capture the signal and create better pictures. But with the improvement of the quality of the scanners, essentially, we do not need to use those coils anymore. We use coils now that sit on the surface of the patient and that has helped tremendously, a lot more men now feel comfortable getting the MRI. In the past, when we had to put in the rectal coil, a lot of men would decline because of the discomfort associated with the coil. 
 
Phillip Koo, MD [00:02:15] Alright, so that’s great news that endorectal coils are not needed. So, in terms of magnet strength, oftentimes we hear, oh, a prostate MRI has to be done on the 3 Tesla, but I think as we all know, there’s many that are done very well on a 1.5 Tesla, so help explain that to us. 
 
Andrei Purysko, MD [00:02:33] Yeah, that is correct. And so technically a 3 Tesla magnet will give you better quality pictures than a 1.5 Tesla by certain types of metrics. But in terms of cancer detection, we have a lot of research that use 1.5 Tesla MRI. So, all the major clinical trials that you see being published these days, all of them include a mix of 1.5 and 3 Tesla. And we know that we have good quality images on a 1.5 Tesla. It has sometimes more to do with the age of the system. So, the newer systems they have. The 1.5 system, they have good quality images that are very comparable to 3 Tesla. And so, I think from an access standpoint, it is important for us to also open up to 1.5 Tesla because more patients will have access to MRI and good quality MRI. 
 
Phillip Koo, MD [00:03:17] Alright, that’s great to hear. So, it doesn’t necessarily mean, 1.5 doesn’t mean you’re not getting the right study because a new MRI that’s 1.5, In many ways, could be better than a 3T that’s a little older. So, talk us through when patients should be getting prostate MRIs. 
 
Andrei Purysko, MD [00:03:36] Yeah, so prostate MRI is being used in a number of different ways, either in the initial detection of prostate cancer or to help define what treatment the patient will be get. There are now some even treatments that are guided by the MRI. And for patients that have been treated, we also can use MRI to detect the recurrence of the cancer. So, MRI is very versatile in terms of prostate cancer because it can be used from the initial diagnosis all the way to the evaluation of recurrence. 
 
Phillip Koo, MD [00:04:02] Alright, so let’s start off with a patient who has an abnormal PSA, they have a suspicion for prostate cancer, what’s the role of MRI in that space? 
 
Andrei Purysko, MD [00:04:12] Yeah, so what the studies show us is that when you use MRI before deciding if the patient needs to get a biopsy, that can help a lot, not only by helping inform the physician where the cancer is located and where they need to do the biopsy, but also to identify patients who actually may not have prostate cancer and don’t need a biopsy. So, the PSA in that initial investigation, the MRI in the initial investigation can really help decrease the number of patients who might be getting a biopsy that it’s unnecessary. 
 
Phillip Koo, MD [00:04:42] Would you recommend that every patient with an abnormal PSA that they’re considering a biopsy get a prostate MRI? 
 
Andrei Purysko, MD [00:04:50] Yeah, so not every man will need an MRI. I think that it’s a discussion that needs to be happening with the urologist because the PSA, as we know, depending on the age or what we could consider normal for certain age groups, that PSA might be within the normal limits. The other thing is that depending on the size of the prostate, which is something that the MRI helps, but patients with larger glands can have higher PSA that doesn’t necessarily mean that the patient have cancer, while sometimes patients with a smaller gland. Even at a lower PSA level, they might have cancer. So not every man will necessarily need an MRI. It’s a discussion that needs to happen with the urologist. 
 
Phillip Koo, MD [00:05:29] So you mentioned the use of MRI to help choose certain treatments. Can you tell us more about that? 
 
Andrei Purysko, MD [00:05:36] Yeah, and so MRIs really changed the paradigm in terms of treatment. Nowadays, in particular, there’s something called focal treatment, which is a type of treatment where we can actually treat the cancerous tissue and spare a lot of the healthy tissue. Whether we’re doing this using different types of energy, like ultrasound energy, we can freeze the tumor, we can use even laser to ablate the tumor or even the conventional treatments too, depending on the type of surgery that the physician is explaining. They could spare some healthy tissue depending on the MRI results. So, MRI is really helping guide and inform patients about what would be the best treatment options available. Because as we know, prostate cancer, there’s a number of ways to be treated. And so, the physicians can inform patients better having that information that traditionally they didn’t have because the other imaging tests like ultrasound or even CT scan were not as good. 
 
Phillip Koo, MD [00:06:30] So let’s say a patient has an abnormal PSA. They get a prostate MRI, an abnormal and a rising PSA they get an MRI. It doesn’t necessarily show a lesion. Should they still get a biopsy or does the MRI say, hey, you know, I don’t see anything. Basically, is the MRI perfect? 
 
Andrei Purysko, MD [00:06:50] Yeah, MRI is not perfect, unfortunately. So, we know that about one in 10 men will have prostate cancer that is not diagnosed on MRI. And when I say one in ten, I say, one in 10 men with aggressive forms of cancer. So, MRI catches the vast majority of the aggressive cancers. We don’t see most of the non-aggressive cancers, but there’s still a number of patients that will have cancer that we do not detect in MRI. So, the way to describe MRI, MRI is a piece of the puzzle. Probably the most important piece of the puzzle, but it’s not the single piece of puzzle. So, the PSA is still extremely important. A family history is very important. So, there are other things that could indicate that the patient might need a biopsy despite a normal MRI. 
 
Phillip Koo, MD [00:07:27] Great, so we know that MRI, prostate MRI is used very often for active surveillance. What’s sort of the performance in that setting and how do you recommend patients be followed? Obviously, every center is gonna have their own protocols but just give us a high-level approach to how to use MRI in active surveillance.
 
Andrei Purysko, MD [00:07:47] Yeah, so MRI can be used in two main ways. One is to decide which men can go into the active surveillance program. So as the triage, so let’s say the patient did not get an MRI before getting the biopsy, that meant if they have an MRI done, studies shows that those patients can be better selected to go into active surveillance or to go in to active treatment depending on what the MRI showed. The second thing is monitoring the cancer long-term. So. MRI can, for patients that we can see the tumor, we could monitor and see if the tumor is changing over time. Unfortunately, MRI in that setting does not replace a biopsy, but the MRI can help physicians trigger if a biopsies is gonna be needed in the future or not. And so, we can use it to triage patients to decide those who might go into active surveillance, and we can monitor longitudinally as well for those patients who have confirmed cancer. 
 
Phillip Koo, MD [00:08:38] All right, so that’s good to know. So even though you get MRIs and active surveillance, you may still need routine or perhaps biopsies based on a trigger that you see on the MRI. Biochemical recurrence is another area in which prostate MRI is used very often. How do you use MRI when you have that rising PSA after surgery or radiation, and how is it different for those patients who receive surgery versus those who receive radiation? 
 
Andrei Purysko, MD [00:09:10] Yeah, so MRI, again, for the local, for the tumors that are recurring locally, MRI is a great test. We also have another test called PSMA PET-CT, which helps detect whether the cancer is spreading outside of the original tumor, but to localize at the treatment bed, whether the prostate is still there or not, MRI is really good. And so, the way it works, MRI can pick up cancers in the surgical bed where the prostate tissue used to be, or if the prostate’s still there, MRI can also help detect the cancer. The problem with the other test that I mentioned, PSMA PET, is sometimes, especially if there’s a lot of the contrast agent tends to accumulate in the bladder. So, the site where the recurrence can happen can be obscured. And so, MRI can help you with certain special techniques detect locally if the cancer has a returned or not. And depending on where the cancer is, the physician can decide what type of treatment comes down the road. Is the patient eligible, for example, If the prostate is still there, is the patient eligible for a radical prostatectomy as a second treatment? Or if the cancer is localized to the treatment bed, it should be radiation plus minus some other type of treatment so MRI can guide physicians in deciding what to do next. 
 
Phillip Koo, MD [00:10:22] So, when you use prostate MRI in this biochemical recurrent setting as opposed to prebiopsy, is the protocol the same or is it a little different? 
 
Andrei Purysko, MD [00:10:32] Yeah, so the protocol for simplicity, we tend to use the same. One major difference is the use of contrast because when we’re doing initial diagnosis of prostate cancer, some studies are coming out now showing that the contrast may not be as helpful, but in the setting of recurrence, giving contrast is really essential because that is the most important factor. We look for tissue that might enhance early, that may show that uptake of the contrast and lighting up on the images immediately after we give the contrast. So, the main difference is that, while for the initial detection, contrast may not be quite as helpful, in the setting of recurrence contrast is really, really essential. 
 
Phillip Koo, MD [00:11:10] That’s a great point. So, let’s talk about patient considerations and perhaps contraindications. I think there’s some groups of patients and it always comes up. You have allergies, you have metal in your body, you have a pacemaker. Sort of dispel some of the myths around those topics. 
 
Andrei Purysko, MD [00:11:26] Yeah, so that’s really important because certain contraindications are becoming less and less common. I would say, for example, the pacemaker, most of the devices nowadays, they’re becoming compatible with MRI. And even the devices that were not originally compatible, they are what we call maybe conditional, which we could potentially use on a 1.5 Tesla system, for examples. So maybe the 3 Tesla might be too strong for the patient to be with a pacemaker inside of the magnet, but with a 1.5 Tesla using certain modifications on the protocol, we can get that patient into the system. So, pacemaker is just one example. There’s a number of other implants that you could have in the body. Like I said, most of them are becoming more and more compatible with MR system, but there’s still a number of patients who unfortunately cannot get an MRI. The other, it’s not a contraindication, but a factor that might influence on the quality of the images is hip implants. We know the prevalence of prostate cancer and the hip implants go hand in hand in this patient population. And so hip implants is one of the things that can degrade image quality. So, it’s not a contraindication. And it’s also hard to tell without actually looking at the images which hip implants will cause problems or not. We know that there are certain types, certain materials for metal that can cause more artifacts than others. Some of the more modern prosthesis, they tend to cause less artifact than some of the older prosthesis. But it’s not a contraindication. So, men can still have, and I would say, majority of the patients, you still can get good quality images. That’s when, again, we talk about the contrast that sometimes we tend to think that we don’t need contrast, but for certain patients that have certain device, whether that is hip implants or UroLift, which is a device to treat the benign prostatic hyperplasia or BPH, in those cases, the contrast can be really helpful. And so, it sort of mitigates the problems. The other issue is contrast allergy, since I’m talking about contrast. Which is a very uncommon thing. At least it’s much less common than the iodinated contrast that we use for CAT scans, for example. So even in those patients, we can also give some medications to prevent more serious reactions. There’s certain patients who have had what we call anaphylaxis, which is the most severe reaction. In those cases, we tend to avoid contrast. But again, there is always an option of doing a non-contrast MRI for those patients unless, as we just talked a minute ago. If it’s a recurrence case. In that situation, we probably need to use a different modality. 
 
Phillip Koo, MD [00:13:47] And then I know contrast there’s some issues with renal function. Can you help explain that for us as well? 
 
Andrei Purysko, MD [00:13:53] Yeah, so that’s another good point. And so, the newer agents that we use in the market, those agents are more stable. So, the molecule of the agent it doesn’t break out. So, what happened is that the older contrast agents, they had a more unstable molecule. So, they tend to break out, and they could accumulate in the body. So, the contrast is primarily excreted by the kidneys. So, in patients where that they had poor renal function with the older contrast agents, there was a serious risk of that contrast creating deposits in the bodies. And that could cause a very severe disease called nephrogenic systemic fibrosis, and patients could actually die of that disease. But with the more moderate agents, that has become much less of a concern. So, we can safely give the newer types of contrast agents, even in patients that have poor renal function. 
 
Phillip Koo, MD [00:14:37] You know, Andrei, you bring up a lot of great points for patients, you know, that are factors that oftentimes we don’t think about. Number one, the equipment. You talked about how the equipment obviously needs to be to a certain standard. The contrast agents used, clearly there’s a difference between what might be used in the past versus what’s used today. Perhaps there’s cost factors there as well. And there’s the human piece, the radiologist piece, where obviously you want someone who’s well-trained reads a lot of these and stays up to date. What type of advice do you have for patients who need to get a prostate MRI where they can make sure they’re going to the best place? 
 
Andrei Purysko, MD [00:15:17] Yeah, so that’s a great question. And so one of the things that patients can do is go to centers where there’s sort of a public relationship between radiology departments and urologists where they collaborate very closely because oftentimes the radiologists get better from the feedback they get from the urologist, from the pathologist, from colleagues, from other specialties, and which is one of reasons why the American College of Radiology created this prostate cancer MRI center designation to really highlight and promote the centers that go above and beyond just, not just by providing great quality images, but also because they have these relationships. They have mechanisms in place that help making sure that the radiologists get feedback from the interpretation of the images, which also goes to the urologist performing the biopsy. So, patients should seek centers that have that sort of established collaboration. Again, the MRI designation would be a good way to look for the centers. But certainly, places where there’s strong collaboration that certainly leads to better outcomes. We know the physicians, they’re learning curve improves as they get more feedback in terms of the interpretation of the images. 
 
Phillip Koo, MD [00:16:24] You know, I think that’s a great point for all patients to know is I always find it like a mark of approval, seal approval if the urologist knows who the radiologists are by name. Oh, that’s Andrei, good. You know I trust that rather than, oh, who’s that random person reading it? So that type of relationship I agree is so, so important. Good. So, we’ve seen a lot of growth in prostate MRI. I think five, seven years ago, it was sort of niche, it was growing slowly. All of a sudden today, patients are getting it left and right. And I know in the past, there have been issues with reimbursement. Can you talk a little bit about just the general sense of reimbursement today and is this service covered for most patients? 
 
Andrei Purysko, MD [00:17:08] Yeah, it has improved a lot. You know, a decade ago or so, you know, we saw that there was still a lot of barriers. Most patients would only be approved for a prostate MRI if they had a prior negative biopsy. And so that has changed significantly. Now insurance companies are approving patients to get an MRI even before the biopsy because they know that, you now, potentially again, not for every patient, but potentially a negative MRI could save a biopsy. And we know biopsy has potential complications, certain risks involved. And so, I think the insurance companies have come to a realization that, you know, offering men upfront that MRI before they commit to a biopsy, for instance, that can have a lot of benefits. And also, in terms of deciding the treatment the man is going to get to guide the therapy, in terms deciding which areas of the prostate needs to be treated. I think all of this together has made it a much more favorable state where men have much more access now to prostate MRI than they had before. There’s an interesting study published from data from CMS, showing that in about 2014, there was 0.5% of the men, a really small percentage of men were getting MRI before biopsy. That number has risen to 35% in 2024. It’s probably higher now, but certainly we’ve seen a significant increase over time in men getting the MRI before they get the biopsy. 
 
Phillip Koo, MD [00:18:26] That’s interesting data and I would argue that number needs to go way higher because there’s so much value in the prostate MRI. So just to sort of bring this to a close What’s next for prostate MRI that will be really game changing for the entire prostate cancer community? 
 
Andrei Purysko, MD [00:18:43] Yeah, there’s so much exciting research going on in prostate MRI. I think that’s one of the things that we love about this field is that there’s constant change. I think, you know, we cannot talk about prostate MRI without talking about artificial intelligence, which is a hot topic in medicine, just in general. I think we’re seeing now data showing that artificial intelligence can have a performance that matches the performance of humans. So, for me as a radiologist, I’m not necessarily afraid of losing my job, but certainly that can augment my capability, make it more efficient, and also help. We’ve seen a number of times where sometimes the AI will pick up the cancer that was not necessarily initially seen by the radiologist. So, in the context of efficiency, artificial intelligence will make us faster, will augment our ability, and hopefully the next step is to try to help us identify not just every prostate cancer, but the prostate cancer, that it’s truly meaningful, the cancer that will progress, that will cause problems in the future. As we know, there are a lot of prostate cancer that is diagnosed that will never cause any harm to the patient. So, I think that the next frontier is, at least for imaging, is to find tools, develop tools, probably with help of artificial intelligence that will help us really identify the meaningful cancers that do need treatment, that will prevent metastatic disease or death in the feature. 
 
Phillip Koo, MD [00:20:01] Well, thank you very much, Andrei. This has been very enlightening. And I think we appreciate you sort of sharing all these tidbits with all of our listeners out there because I think it helps them be more empowered and have more productive conversations with their urologist and their entire team. So, thank you, very much Andrei, for joining us. 
 
Andrei Purysko, MD [00:20:18] Thank you, it was my pleasure. Thank you.