Diagnostic Value of Photon-Counting CT in Subsegmental Pulmonary Embolism
Recruiting now
Conditions studied: Subsegmental Pulmonary Embolism, Photon-Counting Computed Tomography
In brief
Pulmonary embolism (PE) is a serious and potentially life-threatening condition caused by blood clots in the lungs. A particular type, subsegmental pulmonary embolism (SSPE), involves very small branches of the pulmonary arteries. Although these clots occur in smaller vessels, their risk of recurrence and complications may be similar to larger clots. Conventional CT pulmonary angiography (CTPA) is the standard imaging test for suspected PE, but image quality can sometimes be limited by motion artifacts, poor contrast filling, or body habitus, making the detection of SSPE challenging. Photon-counting computed tomography (PCCT) is a new CT technology that provides higher image resolution, lower radiation dose, and improved visualization of small blood vessels. Early studies suggest PCCT may reduce motion artifacts and increase the accuracy of detecting SSPE compared with conventional CT. This prospective cohort study will compare PCCT with dual-source CT in patients with suspected acute PE. The study aims to determine whether PCCT improves the detection rate and image quality for SSPE, and whether it can provide more reliable diagnostic information to guide clinical care.
Key facts
- Study ID
- NCT07575503
- Run by
- Second Affiliated Hospital, Zhejiang University, School of Medicine
- People needed
- 696
- Starts
- 2026-01-01
- Expected to finish
- 2027-01-01
- Last updated by the study team
- 2026-05-08
Who can join
Age: 18 and older. Sex: any. Healthy volunteers: not accepted.
You may qualify if…
- Age ≥ 18 years
- Clinical manifestations supporting the diagnosis of acute pulmonary embolism, including:
- Acute onset or progressive dyspnea Unexplained hypoxemia Chest pain Hemoptysis Syncope or presyncope Combined with abnormal findings on electrocardiogram, echocardiography, or pulse oximetry
- Revised simplified Geneva score ≥ 3
- Written informed consent obtained from the patient or the patient's legally authorized representative
You may not qualify if…
- Patients requiring prophylactic or therapeutic doses of anticoagulant medication for reasons other than venous thromboembolism (VTE).
- Life expectancy less than three months.
- Patients unable to undergo CT scanning due to severe condition or hemodynamic instability.
- History of allergy to contrast media, renal insufficiency (creatinine clearance < 30 mL/min), or ongoing long-term dialysis.
- Pregnancy.
- Refusal to provide informed consent or inability to complete follow-up for any reason.
Where it is running
- The Second Affiliated Hospital of Zhejiang University School of Medicine — Hangzhou, Zhejiang, China (enrolling)
Full record on ClinicalTrials.gov
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