Repositioning the Bolus Tracking ROI to the Superior Vena Cava in CTPA Facilitates Contrast Volum… (NCT07342374) | Clinical Trial Compass
CompletedNot Applicable
Repositioning the Bolus Tracking ROI to the Superior Vena Cava in CTPA Facilitates Contrast Volume Reduction
Malaysia72 participantsStarted 2023-02-01
Plain-language summary
This randomized controlled trial evaluates a protocol optimization for Computed Tomography Pulmonary Angiography (CTPA). The study investigates the impact of repositioning the bolus-tracking region-of-interest (ROI) from the standard pulmonary trunk (PT) to the superior vena cava (SVC). The goal is to compensate for the CT scanner's inherent transit delay time (TDT) to better align the scan with the peak arterial phase. By optimizing this timing, the study assesses whether contrast media volume can be safely reduced by 40% (from 50 ml to 30 ml) while maintaining diagnostic image quality and preventing venous contamination.
Who can participate
Age range
18 Years – 90 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* All patients scheduled for a Computed Tomography Pulmonary Angiography (CTPA) examination.
* Provision of written informed consent by the subject, guardian, or medical specialist.
* Patients with an upper extremity intravenous (IV) line using a 16-20 gauge cannula.
* Patients with a stable heart rate between 60 and 120 beats per minute (bpm).
Exclusion Criteria:
* Pregnancy, breastfeeding, or use of non-reliable methods of contraception.
* Patients with impaired renal function, including acute kidney injury or chronic kidney disease (CKD) with an eGFR less than 30 mL/min/1.73m².
* Patients with a lower extremity IV line, as this bypasses the Superior Vena Cava (SVC) and results in bolus tracking technique failure.
* Patients with a heart rate lower than 60 bpm or higher than 120 bpm.
* Patients with a cannula size of 22g or smaller, as it cannot accommodate the high flow rate (4 mL/s) required by the power injector.
* Patients with severe cardiac impairment or congenital heart disease.
* Patients with a Body Mass Index (BMI) exceeding 35 kg/m², as severe obesity causes beam hardening effects that degrade image quality.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Mean Difference in Hounsfield Unit (HU) Attenuation Between Pulmonary Artery and Pulmonary Vein
Timeframe: At the time of post-procedural image analysis (approximately 48 hours after CTPA scan completion).