Photon-counting CT for detecting subsegmental pulmonary embolism
Application of Photon-Counting Computed Tomography in the Diagnosis of Subsegmental Pulmonary Embolism
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 |
|---|---|
| Enrollment | 696 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | Second Affiliated Hospital, School of Medicine, Zhejiang University Academic / other |
| Drugs / interventions | radiation |
| Locations | 1 site (Hangzhou, Zhejiang) |
| Trial ID | NCT07575503 on ClinicalTrials.gov |
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.
Who should consider this trial
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.
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.
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 performed: 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.
Eligibility criteria
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 this trial is running
Hangzhou, Zhejiang
- The Second Affiliated Hospital of Zhejiang University School of Medicine — Hangzhou, Zhejiang, China (Recruiting)
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.