A new PET radiotracer accurately detects deep vein thrombosis in the legs and reveals whether the blood clot has traveled to the lungs. By enabling whole-body imaging of blood clots in a single scan, this approach could support faster and more efficient diagnosis, especially for patients who also need 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 a collection of images showing visualization of blood clots in the legs and lungs was selected as the 2026 SMMMI Henry N. Wagner, Jr. Image of the Year.
Each year, SNMMI selects images that best illustrate the most promising advances in the fields of nuclear medicine and molecular imaging. The cutting-edge technologies captured in these images demonstrate the ability to improve patient care by detecting disease, aiding diagnosis, increasing clinical confidence, and providing the means to select appropriate treatments. This year, the SNMMI Image of the Year was selected from approximately 1,500 abstracts submitted to the conference.
Deep vein thrombosis is a common condition in which a blood clot forms in the leg and sometimes travels to the lungs as a pulmonary embolism. According to the Centers for Disease Control and Prevention, the disease affects about 900,000 Americans each year. Early detection is important to ensure prompt treatment.
Traditional imaging techniques, such as venous ultrasound and CT, rely on indirect structural changes such as venous compressibility and contrast filling defects, rather than directly visualizing the thrombus itself. 18F-GP1 PET/CT is a thrombus-specific imaging that selectively targets activated platelets, allowing direct visualization of thrombi even in areas that are difficult to assess with conventional imaging. ”
Sangwon Han, MD, PhD, Clinical Assistant Professor, Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
In this study, researchers evaluated the diagnostic accuracy and tolerability of 18F-GP1 PET/CT, a new radiotracer for identifying acute lower extremity deep vein thrombosis. Forty-six symptomatic patients underwent 18F-GP1 PET/CT imaging, and scans were independently evaluated by three blinded nuclear medicine physicians. We compared the diagnostic performance of venous ultrasound to identify femoral thrombi. Calf blood clot detection accuracy and lung blood clot detection rate were also evaluated. Radiotracer safety was evaluated throughout the study.
18F-GP1 PET/CT showed high diagnostic accuracy in detecting blood clots not only in the thigh but also in the calf. We also demonstrated a high detection rate of pulmonary embolism with deep vein thrombosis. 18F-GP1 PET/CT was well tolerated and there were no drug-related adverse events.
“These findings suggest that a single whole-body PET scan can accurately assess blood clots in both the legs and lungs simultaneously, potentially reducing the need for multiple tests while increasing convenience for patients,” Han said.
SNMMI Scientific Program Committee Chair Giuseppe Esposito, MD, believes this radioactive tracer has the potential to change the detection of acute blood clots beyond deep vein thrombosis. “This approach could serve as a platform technology for detecting blood clots throughout the body and could also be useful in detecting stroke and cardiovascular disease. These images show how powerful molecular imaging can be,” he said.
18F-GP1 PET/CT has already been evaluated in phase 2 studies for deep vein thrombosis, as well as diseases such as embolic stroke and cardiovascular disease. With further validation through large multicenter phase 3 trials, this radiotracer could become part of routine clinical practice within the next 5 to 10 years.
sauce:
Society of Nuclear Medicine and Molecular Imaging

