January/February 2026 Issue
Speed and Precision
By Jessica Zimmer
Radiology Today
Vol. 27 No. 1 P. 14
Advances in Parkinson’s Disease Imaging
Medical imaging techniques and equipment are key for diagnosing and treating Parkinson’s disease, a movement disorder caused by the deterioration and death of dopamine-producing brain cells. To better understand this disease, physicians, researchers, and medical equipment manufacturers share information to build a bank of biomarkers. The measurable indicators of Parkinson’s disease, like abnormalities in alpha synuclein, a protein in the nervous system, allow physicians to distinguish Parkinson’s disease from similar neuromuscular disorders.
“Historically, Parkinson’s disease was very much a clinical diagnosis. In early stages, it could be difficult to tell it apart from other diseases,” says Erik Middlebrooks, MD, consultant for the department of radiology of Mayo Clinic Florida. “MRI was often considered a tool to exclude other causes of symptoms. We now use ultrahigh-field MRI machines to provide accurate diagnosis of Parkinson’s disease from mimics.”
After diagnosis, medical imaging also informs the type of treatment and treatment planning. For example, medical imaging has had an increasing role in personalization of deep brain stimulation (DBS). This involves implanting electrodes that send electrical pulses to areas of the brain that control movement.
“Advances in imaging have greatly improved the ability to accurately place the electrodes, as well as allowing more personalized programming for stimulation,” Middlebrooks says. “Patients want an answer as to whether they have Parkinson’s disease and then treatment as soon as possible, rather than a ‘wait and see’ approach.”
In the future, “smart” imaging software to flag tiny changes in brain circuits before the human eye can see them could further assist doctors. “On the hardware side, we are seeing faster MRI machines, better motion correction for tremor and stiffness, and targeted tools like focused ultrasound that use imaging to guide treatment in real time. My hope is that we eventually move from static pictures of the brain to living movies of how brain networks are firing in Parkinson’s,” says Michael Okun, MD, director of the Norman Fixel Institute for Neurological Diseases at the University of Florida. Okun is also the medical advisor for the Parkinson’s Foundation and coauthor of The New York Times best-selling book The Parkinson’s Plan (2025).
Communication Is Key
Despite the information that medical imaging provides, communication with patients and their loved ones is useful for diagnosing and treating Parkinson’s disease. Parkinson’s disease is caused by a variety of factors, from a family history of Parkinson’s disease to exposure to environmental toxins. All parties may have information to share as to why a patient may have Parkinson’s disease. They can also explain aspects of the patient’s history that may confuse or complicate treatment.
In addition, early symptoms of Parkinson’s disease can be mild. Patients and their families may dismiss them or think they are signs of a different concern. Parkinson’s disease is widely known to cause tremors, especially in the foot or jaw, slowed movement, and rigid muscles. Lesser-known symptoms include poor posture and balance, slurring and hesitation when talking, depression, anxiety, sleep problems, constipation, and issues with sexual performance.
Okun tells patients and families that imaging is like a map, not a crystal ball. “Imaging helps us rule in certain patterns and rule out mimics such as stroke, tumor, or normal pressure hydrocephalus (NPH)” he says. “NPH is the build-up of fluid in cavities called ventricles in the brain, which puts harmful pressure on tissues in the brain. Symptoms include nausea, vision problems, and fatigue. In some cases, [imaging] can visualize dopamine circuits directly.”
He says families usually understand physicians are looking for damages to or blockages in the neural wiring. “However, it can be hard to grasp why a scan can look normal even when symptoms are manifesting. We always pair the pictures with the story from the neurological examination,” Okun says.
Imaging Signals
Okun says MRI has arrived as a diagnostic tool that can be used in Parkinson’s, multiple system atrophy, and progressive supranuclear palsy. When he teaches other health care professionals about Parkinson’s disease, he focuses on when imaging changes disease management.
“We spend a lot of time on dopamine transporter scans (DaTscans), MRI red flags for atypical Parkinsonism, and on how to avoid over- or underinterpreting subtle findings,” he says. “Common questions include, When should I order a DaTscan? How do I read neuromelanin or susceptibility images? And, more recently, How do I trust or validate an AI tool that claims to read these scans better than I can?”
A DaTscan is a medical imaging test that involves injecting a radioactive tracer called loflupane, or DaTscan, into the blood. The tracer enters the brain through the blood. It attaches to a dopamine transporter, a molecule on dopamine neurons. A few hours after the injection, imaging equipment is used to scan the head and determine where the tracer is present. A patient with Parkinson’s disease will usually have a smaller signal from the tracer in the striatum, where the ends of the dopamine neurons are located. The tracer signals on both sides of the brain tend to look like irregular periods rather than long commas. A lower amount of tracer signal indicates the patient’s dopamine system is unhealthy.
Neuromelanin is a dark brown intracellular pigment that is associated with Parkinson’s disease. It is found in some neurons. Parkinson’s disease causes these neurons to degenerate, forming inclusions that lead to neuroinflammation. A susceptibility image is made with susceptibility-weighted MRI, which is sensitive to iron concentration. It can help a physician find abnormal iron deposition in the brain, which is a sign of Parkinson’s disease.
Diagnostic and Treatment Tools
Okun says his group is currently focused on imaging the circuits of gait freezing, balance, and cognition in Parkinson’s. The team then links these pictures to genetics, inflammation, and environmental exposures.
“We have been developing MRI as a diagnostic tool and also as a progression marker,” Okun says. “We are interested in predicting who will respond best to DBS, focused ultrasound, or new drug trials. These projects are typically supported by a mix of National Institutes of Health grants, foundation support such as from the Parkinson’s Foundation, and philanthropy from families who want to accelerate progress.”
Focused ultrasound is a therapeutic technology that treats Parkinson’s disease without surgery. It involves beaming ultrasonic energy on targets in the brain. The technique usually aims at several different targets. The beams disrupt the blood-brain barrier, allowing harmful materials to leave the brain more easily. In the future, disruption of the blood-brain barrier might also allow helpful substances to enter the brain.
On the diagnostic side, Middlebrooks says AI is leading to higher quality imaging and faster imaging times. This provides more accurate data for a DaTscan signal and an image showing neuromelanin.
Okun says radiologists and radiologic technologists should see themselves as key members of the Parkinson’s care team, not just image producers. “Details like head positioning, minimizing motion, using the right sequences, and adding a clear, clinically framed report can dramatically change what we do in the clinic and in the operating room,” he says. “I would love for there to be more direct dialogue between imaging teams and neurological centers. [Then we could] synergize in designing protocols and AI tools that can better address the real clinical questions our patients bring to us every day.”
Advanced Scans
The array of diagnostic medical imaging equipment related to Parkinson’s disease is advanced and varied. The quantitative results that imaging equipment provide complement a physical examination and MRI results. Quantitative results are particularly valuable when a patient’s motor symptoms are subtle or atypical. Medical equipment makers are seeking to help physicians diagnose Parkinson’s disease early, with accuracy and confidence.
For example, physicians use available tools such as United Imaging’s uMI PET/CT to perform fluorodopa (F-DOPA) scans. These scans are similar to DaTscans in that they visualize the loss of dopamine nerve terminals in the striatum.
“[This is] a key pathology that enables differentiation of Parkinson’s disease and other Parkinsonian syndromes from other conditions like essential tremor. Essential tremor shows normal distribution, whereas Parkinson’s disease shows reduced dopamine transporter binding,” says Wendy Winkle, vice president of molecular imaging for United Imaging North America. “[F-DOPA scans are] sometimes combined with FDG PET/CT scans to allow assessment of preservation of metabolism. [FDG PET/CT scans] also help differentiate Parkinson’s disease from other syndromes.”
High spatial resolution reveals finer patterns of dopamine loss and metabolism in finite areas such as the posterior putamen, which is connected to the cerebral cortex, thalamus, and brainstem. This is the outermost portion of the basal ganglia, part of the brain that plays a role in motor control. Seeing patterns of dopamine loss and metabolism in this area is essential for early diagnosis.
Winkle sees many advancements on the horizon in 2026. “Extended axial fields-of-view PET enables much faster scanning and/or much lower radiation dose,” she says. “Fast scans can be extremely important for patients with tremors. (Patients with Parkinson’s disease often have trouble controlling their movements.) Fast scans combined with AI-driven motion correction algorithms provide motion-corrected scans with magnificent image quality to enable physicians to make a more confident diagnosis.”
United Imaging uses AI to plan a scan and position a patient with a 3D AI-driven camera workflow. The camera workflow also directs the patient scan and reconstruction.
“The data … are utilized to set parameters for scan coverage, variable milliamperage and kilovoltage peak to lower dose for diagnostic CTs, and more,” Winkle says. “Beyond the scan, our AI-trained reconstruction algorithms like Deep Progressive Reconstruction provide images with reduced noise and higher signal-to-noise ratio. [The AI algorithms] improve image quality and enable lower dose and faster scan times.”
Standardizing Quantification
GE Healthcare’s imaging technologies include its DaTscan (Ioflupane I 123 injection), an FDA-approved radioactive imaging drug. Physicians use it with SPECT imaging to determine whether there has been a loss of dopamine neurons.
“While DaTscan does not distinguish between specific Parkinsonian disorders such as Parkinson’s disease, multiple system atrophy, or progressive supranuclear palsy, it provides meaningful information that supports more accurate and timely clinical decision making,” says Anja Mett, global neurology product leader for GE HealthCare Pharmaceutical Diagnostics.
GE Healthcare pairs its StarGuide SPECT/CT system with DaTQUANT, an adjunct processing software application it developed in 2013. DaTQUANT provides quantitative uptake methods and a designated normals database to more accurately assess individual patients.
“DaTQUANT has proven to be a vital protocol component for an accurate differentiation of Parkinson’s disease from essential tremor,” says Erez Levy, executive director of molecular imaging for GE Healthcare. “Current use of the software has been rather limited so a greater push for education and implementation will be key for its success.”
A 2024 position paper by the European Association of Nuclear Medicine shows that cadmium zinc telluride (CZT)-based SPECT systems can cut scan times in half, compared with traditional methods. “3D CZT systems are even more efficient than older 2D versions because they capture more data and produce impressive images,” Levy says. “This suggests that CZT SPECT delivers image quality that’s at least as good as conventional systems, but in less time.”
In 2026, GE Healthcare will work on making its CZT detector technology more sensitive. “We are also developing new AI algorithms and working to provide detailed and advanced quantitative insights to help make imaging more automated and precise,” Levy says.
According to Mett, GE Healthcare’s key areas of focus for the year include enhanced image reconstruction, AI-enabled processing to support higher-resolution images and potentially shorter acquisition times, more standardized quantification tools to help clinicians detect changes in function relating to dopamine more consistently, and workflow improvements to reduce the burden on technologists and improve the predictability of exams.
Shortening the Diagnostic Process
At the University of California, San Francisco (UCSF), Salil Soman, MD, a neuroradiologist and a member of UCSF’s neuroradiology division faculty, and members of his lab are working on faster ways to obtain high-resolution images of the brain. Currently, by the time a person is diagnosed with Parkinson’s disease, most people have lost 30% to 50% of their dopamine-producing cells in the substantia nigra. This structure in the brain is part of the basal ganglia and helps control body movement.
“We’re working on a number of algorithms to quantify the loss of dopamine-producing neurons in the substantia nigra,” Soman says. “I suspect that better quality inputs are needed. As we build the imaging protocol, we will get the data and do the processing. That will indicate how to make these scans faster.”
UCSF plans to accomplish this task with head-only MRI scanners from GE Healthcare. The machines should be operational by April. “We plan to look at iron deposits in a lot of areas,” Soman says. “We’re also interested in new (radioactive) tracers coming out, which will give other insights as to whether a patient has Parkinson’s, multiple system atrophy, or progressive supranuclear palsy. There are a variety of susceptibility techniques to help differentiate iron deposition patterns.”
This research and high-tech equipment may prove especially helpful to patients suffering from Parkinson’s disease and other conditions, such as seizures. “It is harder to come up with a targeted therapy for those patients. The goal is to be able to sort out the issues that might be caused by Parkinson’s disease and those that might be caused by something else,” Soman says.
Since family history is a factor in Parkinson’s disease, Soman would like to see people whose close relatives have Parkinson’s disease begin getting medical imaging in their late 40s or early 50s. “That way drug interventions and other treatments would have more efficacy,” he says. “The patient likely would not have experienced a major loss of control. For neurodegenerative disorders, including Parkinson’s disease, it’s always better to start earlier rather than later.”
— Jessica Zimmer is a freelance writer living in northern California. She specializes in covering AI and legal matters.
