Have we been getting the straight dope on MRIs? Nope, says myth-busting med physicist
Part I "Physics, bitches," (parphrasing) Jesse Pinkman, 'Breaking Bad.'
By Howard Wolinsky
In a key scene in the hit TV series “Breaking Bad,” crystal meth cooks Walter White and Jesse Pinkman need to find a way to destroy evidence contained on a laptop owned by murdered drug lord Gus Fring.
The anti-heroes hatch a plot to deploy remotely a powerful magnet in a van to wipe the hard drive held in a high-security police evidence facility in the Duke City.
In a test run, we see the magnet erase a hard drive. Pinkman had been a lackluster student in White’s high school chemistry class. But on his journey from meth cook to chef, Pinkman has experienced growing respect for science.
When the hard drive fries, Pink shouts: “Yeah, bitch! Magnets!” High praise indeed.
For those of us on Active Surveillance (AS) for low-risk to favorable intermediate-risk prostate cancer. super-powerful magnets used in magnetic resonance imaging (MRI) scanners are increasingly becoming essential in identifying lesions and helping us and our doctors decide whether we need biopsies to confirm the presence of cancer. MRI data also are needed for targeted biopsies.
My sad experience from the early MRI days
It wasn’t always so. Back in 2010, when I was diagnosed, MRI scanners were just starting to be used to image prostates. And the technology and the skills of technologists and radiologists weren’t as good as they are today—not that they’re great in many cases.
Still, MRIs have been gaining a foothold in the effort to screen men with rising PSAs to identify lesions and help them avoid unnecessary biopsies.
My results were confusing. A random biopsy found a single tiny Gleason 6 cancer. The MRI suggested there were two. Seven years later, I had a follow-up MRI, and no lesions were found at all.
In those early days, we had MRIs after we had had random biopsies. It was ass-backwards then, of course.
Targeted biopsies were not a reality at that point. These days, MRIs are typically first used to see if there might be lesions, and, if lesions are present, then a decision is made on whether to conduct a biopsy.
The late Dr. Gerald Chodak, a UC urologist, grandfather of AS, and a personal friend, suggested that my MRI likely was wrong. He said I could accept the results. But he said he wouldn’t. Hardly, a resounding endorsement of MRIs.
But the technology has improved over the years. MRIs have reached the point that many doctors feel they can rely on them. These days, MRIs typically precede biopsies--though that doesn’t always happen--so they help in deciding if a patient can avoid a biopsy. And if biopsies are deemed necessary, MRI data allows urologists to target the lesions so there is less dependence on those shot-in-the-dark, random biopsies.
Also, more radiologists these days specialize in pelvic MRIs. Patient tip: It’s worth it to find a radiologist who specializes in this area if you’re having an MRI, though that’s not always easy. You’ll likely have to go to an academic medical center.
Many myths persist in MRI-land.
A new active surveillance patient told me recently how his doctor--a major figure in AS-- had just recommended he undergo an MRI with a 3T (Tesla) magnet. He previously was scanned with a Tesla 1.5.
The idea was to get a better image, right?
(The other Tesla.)
3T has been the mantra in patient circles for years.
Busting myths
Bigger magnets are better? Maybe on “Breaking Bad.” It ain’t necessarily so in tghe MRI suite, Gregory Karczmar, PhD, a medical physicist at the University of Chicago, told me, as he busted several myths regarding MRI scanning and suggested a radical change in MRI technology.
Tesla—not the car
First, let’s define Tesla.
The strength of magnetic fields is measured in units of gauss (G) and Tesla (T). 1T is equal to 10,000 G.
The main magnetic field of a 1.5 T MRI magnet is about 30,000 times the strength of the earth's magnetic field. The main magnetic field of a 3T system is 60,000 times the earth's magnetic field.
The magnetic unit--and the electric car--are named for Nikola Tesla, the Serbian-American inventor, electrical engineer, mechanical engineer, and futurist best known for his contributions to the design of modern alternating current electricity.
(Nikola Tesla)
Probably most of us these days have had scans with 3T magnets.
But it turns out bigger isn’t always better, said Karczmar.
(Gregory Karczmar, PhD, and his late best friend Madelaine, who died from cancer.)
MRI heretic
Karczmar overturns the conventional wisdom in his field.
He has a critical perspective of the MRI industry. He views MRI manufacturers as being engaged in a magnetic arms race of sorts to build and market bigger and more expensive magnets when smaller magnets--down to 1T--can achieve the same results and can be made available to a larger market as a screening tool at a cheaper price.
At UChicago, he said, “We do use 3T, and the radiologists are all fans of 3T. But for the prostate, I’m a big fan of 1.5T and I’m trying to convince the radologists and manufacturers [of that]. There are some aspects of the physics of prostate cancer and the prostate itself that give a 1.5T some advantages.”
Size matters--but smaller magnets may be better for prostate scans
(MRI of a Gleason 6 cancer.)
Karczmar maintains that lower-field magnets are better for identifying prostate lesions.
“I’ve been trying to convince the manufacturers that what they really need is a prostate-specific scanner. It should be 1.5T max, maybe even 1T. It should be specialized for pelvic exams,” he said.
The medical physicist bases his position on, well, the physics of MRI and of the prostate.
“It’s physics, bitches” to paraphrase the hapless Jesse Pinkman.
“When you’re in the body the 3T has a signal dropoff. The higher field scanners with 3T are really good for the head and less good for the body. The bigger the person, the worse the problem. And people tend to be big in Chicago,” said Karczmar.
The magnetic field inside an MRI scanner excites protons in water molecules inside cells, the excited protons then relax and release energy that is used to make images.
(MRI of a Gleason 3+4=7)
“The prostate cancer we’re trying to detect has a certain kind of relaxation time that is very short, but it’s much longer at 1.5T than it is at 3T, so it gives you a longer time to observe the signal, You get a boost in signal from going to higher fields, but you lose a lot of that boost because of the mass of the body. You can put higher-performance gradients in low-field magnets. Then, of course, there is accessibility and cost. Lower field scanners are cheaper to maintain and easier and less expensive to site”
“If I lived in Chicago, I would want an MRI, no question. In a lot of places in the country there may not be access to MRI like we have here. Few places have radiologists with expertise in prostate MRI, but here we are very lucky to have leading experts,” Karczmar said.
The vision
He envisions an inexpensive, more cost-effective prostate-specific scanner.
In case you’re considering buying one, the list price for a 3T scanner is $3-$4 million. Hospitals can get deals because they purchase equipment in volume.
“These scanners are multi-purpose and have lots of bells and whistles that are not needed for prostate MRI. If we go to lower field and keep only components needed for prostate MRI – and invest more in the magnetic field gradients that produce diffusion-weighted MRI (a critical method for prostate cancer detection), I think we could produce a scanner for much less – maybe $1.5 million,” Karczmar said.
“Prostate-specific magnets could be shorter than standard clinical magnets – which would reduce the cost further. Also, siting for these magnets is much less expensive – especially if we can make them shorter. If we design a protocol (see story below) that does not require contrast agent injection – these magnets could be sited outside of a hospital, so siting and operation would be much cheaper.”
(No gad? Egads. Check my article on contrast agents in MedPageToday: https://www.medpagetoday.com/special-reports/apatientsjourney/81259) No contast would appeal to a segment of the market, who are worried about the constrast agent crossing the blood-brain barrier despite assurances about advances in gad. And many of us with small lesions simply don’t need contrast. It can be a feature not a bug if MRIs miss these low-risk Gleason 6 cancers.)
Big maintenance costs go along with MRIs--$120,000 to $140,000 per year. Karczmar thinks he can shrink the costs to $75k per year with his prostate-specific MRI scanner.
“ I expect that if we build a magnet only for prostate MRI there is less that can go wrong and less that has to be repaired. For instance, we don’t have to worry about the head coil breaking.
“And there are fewer imaging protocols to maintain. So maintenance costs should go down. I don’t know much about this, but I suspect that helium recycling pumps and helium ‘top off’ each year or two would be cheaper.”
He said it may be possible--but this would add to costs--to increase the diameter of the tube or bore in a prostate-specific/pelvis-focused scanner and reduce claustrophobia, a big concern for some of us. Big bore, means less claustrophobia.
(Read about my adventures in claustrophobia-land and more in an MRI “torture chamber”: https://bit.ly/3TQjS7H)
“If we have a lower field magnet – we could put more money into increasing bore size. Of course, then we are increasing costs again. So if we want a really large bore low field magnet – that could cost as much as a small bore high field magnet.” he said. “We also can make the magnet shorter – because we only want to scan the pelvis – and the person could be scanned with the head outside the magnet. So that could reduce claustrophobia.”
I experienced clautrophobia in my first MRI at UChicago BTW, with my head inside the magnet and with improper hearing protection that resulted in permanent hearing loss, tinnitis. I have done better with machines that allow me to go in feet first.
Karczmar envisions prostate-specific MRI machines placed “in shopping malls and other convenient places, where people can come on their lunch breaks and get a 15-minute scan.”
Researchers at Weill Cornell Medicine /New York-Presbyterian reported in 2018 in the Journal of the American Medical Association: “Prostate MRI costs anywhere from $500 to $2,500 in the United States, depending upon a patient’s insurance coverage. Approximately, 1 million American men are currently sent for prostate biopsy every year. If all of those men received MRI instead, costs could reach $3 billion annually.”
Karczmar has a bolder view of the use of prostate-specific MRIs.
Physicist speaks, manufacturers yawn
He has made his pitch for a specialized pelvic MRI to a couple of manufacturers. He pointed out to them that not only would this be useful for prostate scans, but also scans for women’s issues in the pelvis, such as uterine fibroids and maybe bladder problems.
The manufacturers didn’t buy it.
The medical physicist said: “There are a lot of possible applications. The manufacturers are reluctant to put a lot of money into this because it’s a paradigm changer and that means it is difficult to guarantee it will pay off. One high-level executive told me that they felt this was a niche market.
“That’s unlikely because the number of people who need prostate cancer screening in the U.S. alone is huge, and then if you include uterine fibroids, bladder issues, and other pelvic exams, it’s massive. If MRI became the standard for prostate cancer screening, there would be more MRI scans every day for prostate than all the other MRIs scans put together.”
He said this could amount roughly to 5 million first-line prostate screening MRIs a year. That represent a revolution in prostate care.
These screening scans typically are done in men in the gray zone of PSAs 4-9, where there is a clinical suspicion of prostate cancer.
“I think as MRI methods improve and confidence in MRI increases and costs go down, the PSA cutoff will also go down,” he said.
“If you have widespread ability of MRI screening, you might start screening people who have what’s considered to be a fairly low PSA, like maybe 2. Then, there would be a lot of people screened,” he said.
Some skepticism
James Hu, MD, the Ronald P. Lynch Professor of Urologic Oncology at Weill Cornell Medicine and director of the LeFrak Center for Robotic Surgery at NewYork-Presbyterian/Weill Cornell Medical Center, argues that significant limitations — including cost and radiology expertise — stand in the way of fully implementing MRI as the primary diagnostic tool for prostate cancer.
“What we want people to understand is that there are significant challenges to accepting wholesale that MRI should be the new standard of care,” said Hu, who has been involved in research showing the benefits of MRI “and the benefit of MRI’s increased diagnostic capabilities needs to be balanced against those costs.”
Hu said another barrier to MRI implementation is lack of expertise amongst radiologists. “There are many community hospitals in the United States that don’t even do prostate MRI,” said Hu. “And those that do may not have accurate readings. In fact, studies have shown that prostate MRI results from community hospitals only agree with those done at high-volume, expert facilities 54 percent of the time.
“The test is only valuable if the results are accurate, and right now, we can’t guarantee that across the board.”
Karczmar said: “I agree with the concerns Dr. Hu raises. We need to get the costs of MRI down and the reliability up. I think we can get the cost for a routine first-line scanner down to maybe $200-300, including evaluation by radiologists. We’ll get the evaluation time down to one minute. That is why we need prostate-specific scanners, automated analysis, and cancer detection, scanners that can be sited inexpensively. And we need improvements in reliability. But I think all of that will come fairly soon.”
Nikola Tesla would approve.
7T? Over the top
OK, some of you may have heard about the 7T scanner. You may even want to give it a spin based on the thought that bigger is better, right?
Forget it, said Karczmar.
7T scanners are research tools with very tight bores that would trigger more claustrophobic reactions than your average MRI scanner.
Meanwhile, “It’s like the wild, wild west with the manufacturers. There is not enough regulation. Manufacturers want to get a good MRI scan, but there is tremendous economic pressure on them. They have to try to make the most possible money and spend as little money as possible to validate their equipment and methods. Advocates could change that calculation by demanding more validation and more cost-benefit analysis,” Karczmar said.
He hopes patient advocates will help him form a consortium for breast and prostate cancer screening with MRI to move this idea forward by pressuring the manufacturers.
Is any patients out there with deep pockets? How about financier-PCa patients Warren Buffett or Michael Milken, founder of the Prostate Cancer Foundation? Are you listening?
(Michael Milken, left, founder of PCF, and Dr. Charles Ryan, CEO of PCF, at NYC at funraiser in NYC that raised $4 million. Mike, can you spare us a dime for a prostate-specific MRI?)
(Another filthy rich PCa patient, Warren Buffett.)
Or maybe we can enlist Elon Musk. This guy may not have prostate cancer—yet—but he does know a thing or two about Teslas.
(Elon Musk, help us out.)
Come on, Money Bags, don’t cheap out. You could probably make some big bank with this new tech.
“I really want the manufacturers to develop a prostate cancer-specific magnet. And also a breast-specific magnet would make a huge difference,” the medical physicist said.
Is he dreaming the impossible dream?
“It would take about 30 million dollars to get it started, so that should be easy,” he joked.
“The manufacturers don’t want to make the investment and take the risk that is involved in changing the paradigm for prostate (or breast) MRI. There is really no pressure on them to do it. If there were a very large patient advocacy group that pushed for this, it could happen.”
Fingers crossed.
One of the biggest puzzles faced by people with prostate cancer is what to eat.
Dr. Geo is promising the scoop on eating for the holidays at 9 p.m. Tuesday Nov. 22.
Register in advance for this meeting on zoom.
https://us06web.zoom.us/meeting/register/tZMudu2vqTojE937zBgx-ubM20i5BJbZXrit
So, here's the link for the recent podcast on how to eat to live healthier and longer.
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