Photon-counting CT for detecting subsegmental pulmonary embolism
Official title: Application of Photon-Counting Computed Tomography in the Diagnosis of Subsegmental Pulmonary Embolism
Run by Second Affiliated Hospital, Zhejiang University, School of Medicine · NCT07575503 · Data updated 2026-11-12
This study will see if photon-counting CT finds very small pulmonary emboli more accurately than standard dual-source CT in adults with suspected acute pulmonary embolism.
Quick facts
| Study type | Observational |
|---|---|
| Ages | 18 Years and up |
| Sex | All |
| Enrollment | 696 (estimated) |
| Sponsor | Second Affiliated Hospital, Zhejiang University, School of Medicine Academic / other |
| Drugs / interventions | radiation |
| Locations | 1 site (Hangzhou, Zhejiang) |
| Status | Recruiting |
| Started | January 1, 2026 |
| Main results expected | September 2026 |
| Study ends | January 2027 |
| Registry record updated | May 8, 2026 |
| Trial ID | NCT07575503 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Adults aged 18 or older who present with symptoms suggesting acute pulmonary embolism, have a revised simplified Geneva score ≥3, and can safely undergo contrast-enhanced CT and provide informed consent are the ideal candidates.
✕Probably not a fit
Patients who are pregnant, have severe renal insufficiency, are allergic to iodinated contrast, are hemodynamically unstable, on anticoagulation for other reasons, or have life expectancy under three months are unlikely to benefit from participation.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This is a prospective observational cohort comparing photon-counting CT (PCCT) with dual-source CT in adults presenting with clinical suspicion of acute pulmonary embolism. The primary outcome is the detection rate of subsegmental pulmonary embolism (SSPE); secondary outcomes include image quality scores, radiation dose, and related imaging metrics. Eligible participants are adults (≥18) with signs or symptoms consistent with PE and a revised simplified Geneva score ≥3, while patients with contraindications to contrast, pregnancy, severe renal impairment, hemodynamic instability, or life expectancy under three months are excluded. The study is conducted at The Second Affiliated Hospital, Zhejiang University School of Medicine, using PCCT’s higher spatial resolution and spectral capabilities to attempt improved visualization of small pulmonary arteries.
Why it matters
Potential benefit: If successful, PCCT could improve detection of very small pulmonary clots while reducing radiation exposure, helping clinicians make more accurate treatment decisions.
How similar studies have gone: Early pilot studies and technical reports indicate PCCT improves image quality and may enhance visualization of small pulmonary vessels, but large-scale clinical validation for SSPE detection remains limited.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. Age ≥ 18 years 2. 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 3. Revised simplified Geneva score ≥ 3 4. Written informed consent obtained from the patient or the patient's legally authorized representative Exclusion Criteria: 1. Patients requiring prophylactic or therapeutic doses of anticoagulant medication for reasons other than venous thromboembolism (VTE). 2. Life expectancy less than three months. 3. Patients unable to undergo CT scanning due to severe condition or hemodynamic instability. 4. History of allergy to contrast media, renal insufficiency (creatinine clearance \< 30 mL/min), or ongoing long-term dialysis. 5. Pregnancy. 6. Refusal to provide informed consent or inability to complete follow-up for any reason.
Where it's running
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The Second Affiliated Hospital of Zhejiang University School of Medicine
Hangzhou, Zhejiang, China Recruiting
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.