What’s next for MRI and cancer research? Using hyperpolarized MRI to see treatment impact faster
Magnetic resonance imaging (MRI) is a type of imaging test that’s used to diagnose cancer and monitor tumor growth.
“MRI is an excellent tool to visualize cancer growing inside the body, but there’s always room for improvement,” says imaging physicist James Bankson, Ph.D.
We spoke with Bankson and head and neck surgeonStephen Lai, M.D., Ph.D., to learn how MD Anderson physicians and researchers are finding new ways to improve MRI and use the latest advances in medical imaging technology to improve cancer treatment.
What does an imaging physicist do?
Bankson: At MD Anderson, imaging physicists work behind the scenes to support medical imaging, including MRI, computed tomography (CT) scans, interventional radiology, mammography and more. We specialize in the underlying physics of how each piece of equipment measures and uses information to create a picture of what’s going on inside the body. We help ensure patients and physicians receive high-quality imaging for diagnosis and treatment planning.
Imaging physicists and imaging scientists also research new ways to use and improve all forms of medical imaging, such as MRI.
How does MRI work?
Lai: MRI uses a strong magnet and radio waves, rather than radiation, to create pictures of soft tissue and organs. This is different than a CT scan, which uses X-rays from different angles, or positron emission tomography (PET), which uses safe radioactive tracers. When you lie on the table and enter the MRI tube, you’re actually going inside a giant magnet. That’s why you can’t have certain kinds of metal on or inside your body during an MRI. An MRI uses views from different angles to build a picture of your tumor and the surrounding tissue. Sometimes patients are given a contrast dye to create a more detailed picture.
How is MD Anderson improving MRI?
Bankson: One of the main projects that my lab is focused on is bringing hyperpolarized (HP) carbon-13 MRI to cancer treatment and research. “Hyperpolarized” means that the signal is amplified to around 100,000-fold higher compared to a normal MRI. This is very difficult to do, but it all happens behind the scenes. A patient receiving an HP-MRI wouldn’t notice much difference from a regular MRI with contrast dye because it uses the same MRI machine.
However, creating a contrast solution to amplify the signal that high requires extreme conditions that stretch the laws of physics in our favor. It’s like putting the contrast dye in a microwave, inside another powerful magnet and inside a freezer at -458° F, all at once. To address this challenge, we use a special machine for a process called dynamic nuclear polarization. It produces hyperpolarized 13-C-pyruvate, a solution that’s completely safe to inject during an MRI scan.
What can amplifying the MRI signal allow us to see that a normal MRI can’t?
Bankson: HP-MRI doesn’t just produce a more detailed picture of the tumor size and location, it also lets us see molecular interactions within the tumor. Cancer cells have an altered metabolism, known as the Warburg effect, which allows the cells to produce energy and biomass for tumor growth. With HP-MRI, we can see this process unfold within the tumor. That’s something we can’t see on a normal MRI.
How is MD Anderson pioneering the development and implementation of HP-MRI?
Lai: We’ve been studying tumor metabolism in the lab and working on HP-MRI for the past decade, and we opened our first clinical trial in 2020. Only 10 other places in the world are using HP-MRI in clinical trials right now. MD Anderson is the first to use HP-MRI for thyroid cancer and will soon expand use to more head and neck cancers.
How will this HP-MRI research benefit patients?
Lai: One of my areas of clinical and research focus is anaplastic thyroid cancer, a very aggressive and deadly cancer. Through our FAST clinic, we’ve made a lot of progress in recent years to make sure these patients receive treatment and access to clinical trials quickly, but time is still on the cancer’s side.
The eventual goal of our clinical trial is to use HP-MRI to determine whether a treatment is working based on changes in tumor metabolism long before the tumor begins to physically shrink. This is the change we watch for with a regular CT scan or MRI. If we can tell within days that a treatment isn’t working, we might have time to switch to a different treatment before the cancer grows out of control, as often happens with anaplastic thyroid cancer. Right now, it can take weeks to determine if treatment is working, which can limit our options when treating such aggressive cancers.
While our research is still in very early stages, we’re excited to bring a new technology into clinical trials and look forward to providing new hope for cancer patients.