Non-Contrast 4DCT to Detect Pulmonary Thromboembolic Events
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|ClinicalTrials.gov Identifier: NCT03183063|
Recruitment Status : Completed
First Posted : June 9, 2017
Last Update Posted : October 18, 2019
Deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, typically in the lower extremities. Pulmonary embolism (PE) occurs when a DVT clot (or fragment) breaks free and travels through the heart to the pulmonary arteries (having to do with the lungs) and lodges in an artery causing a partial or complete blockage. PE is difficult to diagnose due to the non-specific signs and symptoms patients have with this condition such as a cough, shortness of breath, increased heart rate, blood tinged sputum, low oxygen levels.
The standard test to diagnose PE is the Pulmonary Computed Tomography Angiogram (CTA). This can be prohibitive with some patients due to the amount of radiation exposure as well as the complications associated with the need to use intravenous (IV) contrast. In this study the investigators are looking at an alternative method of diagnosing PE's in the Emergency Department where the investigators look at the breathing and blood flow to the lungs thru respiratory gated non-contrast CT (commonly called 4DCT).
The investigators hypothesize that respiratory induced blood mass change in the lungs will allow the identification of under-perfused lung regions.
Cohort 1: 15 participants will be enrolled with a diagnosis of PE by CTA. Each will receive SPECT/CT and 4DCT imaging on the same day. Respiratory induced blood mass change images will be issued from the 4DCT and compared to the SPECT/CT images.
Cohort 2: 5 participants will be enrolled under the same criteria and study procedures as Cohort 1. The participants in Cohort 2 will have the addition of Bilevel Positive Airway Pressure (BiPAP) during the 4DCT imaging.
Cohort 3: 124 participants will be enrolled. Study procedure will be 4DCT only. Participants must be having or have had a CTA to rule out PE. This cohort of the study will be using 4DCT to compare negative CTA to positive CTA findings.
|Condition or disease||Intervention/treatment||Phase|
|Pulmonary Thromboembolisms Pulmonary Embolism||Device: 4DCT and SPECT/CT Device: 4DCT with BiPAP and SPECT/CT Device: 4DCT with CTA in suspected PE||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||149 participants|
|Intervention Model:||Sequential Assignment|
|Intervention Model Description:||
Patients will be imaged with SPECT/CT and 4DCT to compare perfusion with the respiratory induced blood mass changed (RIBMC) defect. Each patient will have both imaging studies performed on the same day.
15 subjects will be enrolled into Cohort 1 and will receive SPECT/CT and 4DCT imaging as described. After those are enrolled another 5 subjects will be enrolled into Cohort 2 and will receive SPECT/CT and 4DCT imaging as previously described with the first 4DCT being obtained with normal breathing and the second scan being obtained with positive pressure breathing via BiPAP. Cohort 3 will enroll 124 participants with clinical suspicion of PE, who will be or have had CTA imaging. 4DCT imaging will be performed for these study participants.
|Masking:||None (Open Label)|
|Official Title:||A Novel Method to Detect Pulmonary Thromboembolic Events With Non-Contrast 4DCT|
|Actual Study Start Date :||April 12, 2017|
|Actual Primary Completion Date :||April 23, 2019|
|Actual Study Completion Date :||April 24, 2019|
Experimental: 4DCT and SPECT/CT
15 patients with segmental or lobar pulmonary emboli on CTA. Each will receive SPECT/CT and 4DCT imaging on the same day. Both 4DCT scans will be obtained with normal breathing.
Device: 4DCT and SPECT/CT
Each patient will receive two 4DCT followed by SPECT/CT.
Experimental: 4DCT with BiPAP and SPECT/CT
5 patients with segmental or lobar pulmonary emboli on CTA. Each will receive SPECT/CT and 4DCT imaging on the same day. The second of the two 4DCT scans will be obtained with positive airway breathing via BiPAP.
Device: 4DCT with BiPAP and SPECT/CT
Each patient will receive two 4DCT, with the second scan obtained with positive pressure breathing via BiPAP, followed by SPECT/CT
Experimental: 4DCT with CTA in suspected PE
124 participants with CTA ordered/performed for suspected PE will be enrolled to have 4DCT. 62 with positive CTA results for PE and 62 with negative CTA results for PE will be included.
Device: 4DCT with CTA in suspected PE
Each patient will receive 4DCT before or after CTA for suspected PE
- Correlation of 4DCT identified perfusion defects with SPECT/CT identified perfusion defects [ Time Frame: 1 hour ]Three experts will delineate hypo-perfused regions of interest (ROIs) on SPECT perfusion and deficit ROIs on respiratory induced blood mass change (RIBMC). Spatial overlap between hypo-perfused ROIs on SPECT perfusion (standard) and deficit ROIs on RIBMC will be assessed using Dice similarity coefficient (DSC).
- Count of patients with true positive detection of PE using contrast-free 4DCT functional imaging (sensitivity) [ Time Frame: 48 hours ]For each case, an expert reader will determine if functional deficits exist within CT-V and RIBMC. The patient will be classified as PE positive if the reader confirms the presence of two or more mismatched segmental or subsegmental defects between CT-V and RIBMC images. This CT-functional imaging (CT-FI) binary classification indicator will be acquired for each patient and compared to the result from the standard acquired CTA. Data will be reported as count of participants determined to have PE by both imaging modalities (true positives).
- Count of patients with true negative detection of PE using contrast-free 4DCT functional imaging (specificity) [ Time Frame: 48 hours ]For each case, an expert reader will determine if functional deficits exist within CT-V and RIBMC. The patient will be classified as PE negative if the reader cannot confirm the presence of two or more mismatched segmental or subsegmental defects between CT-V and RIBMC images. This CT-functional imaging (CT-FI) binary classification indicator will be acquired for each patient and compared to the result from the standard acquired CTA. Data will be reported as countr of participants determined not to have PE by both imaging modalities (true negatives).
- Measure and correlate the 4DCT re-imaging variance of RIBMC images [ Time Frame: 1 hour ]We will repeat the same 4DCT process for the second set of images and measure the variance of ROIs and perfusion deficit on RIBMC between the first and second 4DCT.
- Measure and correlate the airway pressure variance of RIBMC images [ Time Frame: 1 hour ]Three experts will review and delineate any differences of hypo-perfused regions of interest (ROIs) on 4DCT and deficit ROIs on RIBMC with normal breathing versus positive pressure airway via BiPAP breathing using Dice similarity coefficient (DSC).
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03183063
|United States, Michigan|
|William Beaumont Hospital|
|Royal Oak, Michigan, United States, 48073|
|Principal Investigator:||Thomas Guerrero, MD, PhD||Beaumont Health|