NCT07031336 · Duke University
Photon-counting CT in Chest Imaging
What this study is about
Purpose and objective: This project aims to evaluate photon-counting computed tomography (PCCT) quantitative accuracy using COPDGene subjects. The goal is to establish acquisition protocols for PCCT scans with proper post-processing (e.g., reconstruction parameters and harmonization techniques) that enable reproducible measurements of emphysema metrics (e.g.
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Purpose and objective: This project aims to evaluate photon-counting computed tomography (PCCT) quantitative accuracy using COPDGene subjects. The goal is to establish acquisition protocols for PCCT scans with proper post-processing (e.g., reconstruction parameters and harmonization techniques) that enable reproducible measurements of emphysema metrics (e.g., Perc15, LAA-950, HU accuracy) and airways (Pi10, WA%) in the lungs. Study activities and population group: The study will recruit subjects from a current study at Duke (COPDGene Phase 4, Pro00113442). Here are the aims: * The research team will request consent from participants to acquire PCCT scans at their Phase 4 COPDGene visit. Scans will be performed using a PCCT-specific protocol. * Reconstruct the PCCT images with multiple post-acquisition parameter settings. Apply harmonization techniques that are recently developed by the investigators of this study. Data analysis: * Identify the reconstruction and harmonization conditions that enable reproducible measurements of emphysema metrics (perc15, LAA-950, HU accuracy) and airways (Pi10, WA%), when compared to the counterpart EICT scans. * Demonstrate the non-inferiority and potentially improved capabilities of PCCT scans in cross-sectional and longitudinal studies. Risk/safety issues: The participants are asked to get an additional CT scan with a PCCT scanner at their COPDGene Phase 4 visit. This additional CT scan will be done using an inspiratory chest protocol with a total of 3 mGy (\~1.5 mSv) radiation dose. This is roughly equivalent of 6 month of background radiation. Women who are pregnant will not have a chest CT scan done until they are confirmed to be not pregnant.
Interventions
DEVICE
Photon-counting CT
The participants will receive a photon-counting CT scan as part of this protocol.
DEVICE
Energy-integrating CT
The participants will receive an energy-integrating CT scan as part of the main study (NCT00608764).
Primary outcome measures
Quantitative reproducibility as measured by consistency of Perc15 (15th Percentile of lung CT histogram in Hounsfield Unit)
Time frame: Day of Study Visit, approximately 30 minutes
Perc15 will be measured from CT images, and its reproducibility will be quantified. The reproducibility of the measurements is defined as the least significant difference between two consecutive measurements across imaging conditions using the within-subject standard deviation method. The 95% confidence interval for reproducibility will be generated using a bootstrapping method with 5000 samples.
Quantitative reproducibility as measured by consistency of LAA-950 (Percentage of CT lung voxels below -950 Hounsfield Units)
Time frame: Day of Study Visit, approximately 30 minutes
LAA-950 will be measured from CT images, and its reproducibility will be quantified. The reproducibility of the measurements is defined as the least significant difference between two consecutive measurements across imaging conditions using the within-subject standard deviation method. The 95% confidence interval for reproducibility will be generated using a bootstrapping method with 5000 samples.
Quantitative reproducibility as measured by consistency of WA% (proportion of the airway wall area to the total airway area)
Time frame: Day of Study Visit, approximately 30 minutes
WA% will be measured from CT images, and its reproducibility will be quantified. The reproducibility of the measurements is defined as the least significant difference between two consecutive measurements across imaging conditions using the within-subject standard deviation method. The 95% confidence interval for reproducibility will be generated using a bootstrapping method with 5000 samples.
Quantitative reproducibility as measured by consistency of Pi10 (square root of airway wall area for a hypothetical airway with a 10 mm lumen perimeter)
Time frame: Day of Study Visit, approximately 30 minutes
Pi10 will be measured from CT images, and its reproducibility will be quantified. The reproducibility of the measurements is defined as the least significant difference between two consecutive measurements across imaging conditions using the within-subject standard deviation method. The 95% confidence interval for reproducibility will be generated using a bootstrapping method with 5000 samples.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- This study recruit from the Duke-COPDGene Phase 4 study. All participants from this cohort is eligible and they will be included if they consent.
Exclusion criteria
- This study recruit from the Duke-COPDGene Phase 4 study. All participants from this cohort is eligible and they will be included if they consent.
Where
- Durham, North Carolina
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jan 28, 2026 · Source of record for eligibility and locations