Diagnostic Value of Photon-Counting CT in Subsegmental Pulmonary Embolism
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18+
SponsorSecond Affiliated Hospital, School of Medicine, Zhejiang University
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Age ≥ 18 years
Revised simplified Geneva score ≥ 3
Written informed consent obtained from the patient or the patient's legally authorized representative
Disqualifiers
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.
Trial population
Adults (≥18 years) presenting with clinical symptoms and signs suggestive of acute pulmonary embolism will be enrolled. Eligible patients are those with a simplified revised Geneva score ≥3 and abnormal findings on electrocardiogram, echocardiography, or pulse oximetry, which support the suspicion of pulmonary embolism. Patients will be prospectively recruited from the emergency department and inpatient wards of the Second Affiliated Hospital, Zhejiang University School of Medicine. The study population is representative of patients with suspected acute pulmonary embolism who require CT pulmonary angiography for diagnostic confirmation.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
Not listed
Trial groups
696 Participants
are grouped into 2 trial groupsGroup A: Group 1Title: Conventional CT group
Group B: Group 2 Title: Photon-counting CT group
Trial outcomes
Primary outcomes
1
Detection rate of subsegmental pulmonary embolism (SSPE) using photon-counting CT versus dual-energy CT
The proportion of patients with suspected acute pulmonary embolism in whom SSPE is detected on photon-counting CT compared with dual-energy CT. All scans will be independently assessed by two blinded radiologists to determine diagnostic yield.
Time frame
perioperative periodSecondary outcomes
1
Objective image quality scores for SSPE diagnosis
ignal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR) will be calculated based on CT attenuation and image noise measured in standardized Regions of Interest (ROIs) within pulmonary vessels, the aorta, and paraspinal muscles. Higher SNR and CNR values indicate better objective image quality.
Time frame
perioperative period2
Subjective image quality scores for SSPE diagnosis
Radiologists will qualitatively assess image noise and motion artifacts using a 5-point Likert scale (1 = Unacceptable, 5 = Excellent). The average score of the readers will be used, with higher scores indicating better subjective image quality
Time frame
perioperative period3
Incidence of Venous Thromboembolism (VTE)
Occurrence of symptomatic VTE, defined as Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE), confirmed by objective imaging upon clinical suspicion
Time frame
3 monthsSponsors and contacts
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Source ClinicalTrials.gov