Los Angeles -- A novel PET radiotracer can accurately
detect deep vein thrombosis in the legs and reveal whether clots have migrated
to the lungs. By enabling whole‑body imaging of blood clots in a single
scan, the approach may support faster and more efficient diagnosis -- particularly
for patients who also require evaluation for potentially life‑threatening
pulmonary embolism. This research was presented at the Society of Nuclear
Medicine and Molecular Imaging (SNMMI) 2026 Annual Meeting, and the collection of
images showcasing the visualization of blood clots in the legs and in the
lungs, has been selected as
the 2026 SNMMI Henry N. Wagner, Jr., Image of the Year.
Each year, SNMMI chooses an image that best exemplifies the
most promising advances in the field of nuclear medicine and molecular imaging.
The state-of-the-art technologies captured in these images demonstrate the
capacity to improve patient care by detecting disease, aiding diagnosis,
improving clinical confidence, and providing a means of selecting appropriate
treatments. This year, the SNMMI Image of the Year was chosen from nearly 1,500
abstracts submitted for the meeting.
Deep vein thrombosis is a common disease in which blood
clots form in the legs, and in some cases, travel to the lungs as a pulmonary
embolism. It affects approximately 900,000 Americans a year according to the
Centers for Disease Control and Prevention. Early detection is critical to
ensure prompt treatment.
"Conventional imaging techniques, such as venous ultrasound
and CT, rely on indirect structural changes -- like vein compressibility or
contrast filling defects rather than directly visualizing the clot itself," said
Sangwon Han, MD, PhD, clinical assistant professor in
the Department of Nuclear Medicine at Asan Medical Center, University of Ulsan
College of Medicine in Seoul, Korea. "18F-GP1 PET/CT is a thrombus-specific
imaging that selectively targets activated platelets, allowing blood clots to
be visualized directly even in areas that may be difficult to assess with
conventional imaging."
In the study, researchers assessed the diagnostic accuracy
and tolerability of a novel radiotracer, 18F-GP1 PET/CT, for identifying acute
lower extremity deep vein thrombosis. Forty-six symptomatic patients underwent 18F-GP1
PET/CT imaging, with scans independently evaluated by
three blinded nuclear medicine physicians. Diagnostic performance for identifying
clots in the thighs was compared with venous ultrasound; accuracy for detecting
calf clots and detection rate for lung clots was also evaluated. Radiotracer
safety was assessed throughout the study.
18F-GP1 PET/CT showed high diagnostic accuracy for detecting
clots not only in the thigh but also in the calf. It also demonstrated a high
detection rate of pulmonary embolism occurring together with deep vein
thrombosis. 18F-GP1 PET/CT was well tolerated, with no drug-related adverse
events.
"These findings suggest that a single whole-body PET scan
could accurately evaluate clots in both the legs and lungs at the same time,
potentially reducing the need for multiple tests while improving patient
convenience," said Han.
Giuseppe Esposito, MD, SNMMI Scientific Program Committee
chair, see the potential for this radiotracer to transform the detection of acute
thrombus beyond deep vein thrombosis. "This approach could serve as a platform
technology for detecting clots throughout the body and even help to detect
stroke or cardiovascular disease, he said. These images show just how
powerful molecular imaging can be."
18F-GP1 PET/CT has already been evaluated in Phase 2 studies
for deep vein thrombosis, as well as in conditions such as embolic stroke and
cardiovascular disease. With further validation through larger, multicenter Phase
3 trials, this radiotracer could become part of routine clinical practice
within the next five to 10 years.