The study did not reach its enrollment target due to a relatively narrow time window for imaging after the contrast CT imaging confirmed PE and limitations in the availability of the tracer and the PET scanner.

This study aims to investigate a novel positron emission tomography(PET)-probe for imaging of fresh intravascular blood clots in pulmonary embolism (PE) and deep venous thrombosis (DVT).

Venous thromboembolism (VTE) is one of the most common causes of death in the United States, resulting in more than 100,000 deaths annually. Current diagnostic techniques rely on indirect measures of clot for diagnosis and therefore suffer from the problems of both under and overdiagnosis and cannot always be performed on patients with renal failure and lung disease. In this study, we will use the novel fibrin-specific probe 64CU-FBP8 (Copper-64 labeled fibrin binding probe 8) for PET imaging of fresh blood clots in PE and DVT. Our long-term goal is to establish a novel thrombus body scan (TBS) using 64CU-FBP8 for PET imaging to overcome the limitations of indirect venous thromboembolism diagnosis, and, with one single test, provide a total-body assessment of fresh intravascular clot.

Inclusion Criteria:

• 18 years of age or older with a clinically significant pulmonary embolus (PE) confirmed by a filling defect in CT angiography (CTA), and
• Subjects must receive the radiotracer injection within 72 hours of their diagnosis.

Exclusion Criteria:

• Subjects < 18 years of age
• Time of expected radiotracer injection > 72 hours from the time of a positive venous duplex ultrasound or CT- angiogram
• Women subjects of childbearing potential who are pregnant, seeking to become pregnant, or have a positive serum pregnancy (beta-HCG) test
• Unable to lie flat for 45 minutes as assessed by physical examination and medical history (e.g. back pain, arthritis, dyspnea),
• Weight that exceeds the PET camera table limit (300 kg)
• The subject will not be enrolled in the study if the radiation exposure for research studies during the prior 12 months, combined with the exposure from this study would exceed 50 mSv (millisievert).
• Due to the radiation exposure from imaging studies, all women of childbearing potential will be required to have a negative serum pregnancy test performed prior to any imaging procedures on the same day (if not already done that day). Patients with a positive serum pregnancy test will be excluded. Breast feeding women will also be excluded.
• A pre-existing condition or use of a medication including vasopressors and tPA (tissue Plasminogen Activator) that in the opinion of the investigator may place the subject at a substantially increased risk
• Hemodynamic instability, including requiring escalating doses of vasopressor medication.
• No groups designated as "special vulnerable populations" will be studied.
• No exclusions will be made based on race, sex, or ethnic origin.
• 64Cu-FBP8 (Copper-64 labeled fibrin binding probe 8) is cleared by the kidneys, patients with eGFR (estimated Glomerular Filtration Rate ) < 30 will be excluded.

Including all recruited participants.

After 64Cu-FBP8 injection, during PET imaging, and 24 hours monitoring. The all-cause mortality is based on the last follow-up after 12 months, including the participant who withdrew from the study.