The overall goal of this project is to compare the absolute quantification of myocardial perfusion done by using CT myocardial perfusion imaging (CT-MPI) and the coronary flow measured by using CT Fractional Flow Reserve analysis (CT-FFR) to the gold standard represented by PET myocardial perfusion imaging (PET-MPI).
Participants will be patients who are scheduled to undergo PET Myocardial Perfusion Imaging, which is the traditional method for evaluating patients with suspected blockages or narrowing of the heart vessels (coronary artery disease) causing impaired blood to flow to the heart muscle (myocardium). The purpose of the study is to determine and compare the newest heart imaging equipment which allows the non-invasive evaluation of coronary anatomy, coronary flow and myocardial perfusion in patients with suspected or proven coronary artery disease (CAD) with the actual gold-standard for quantitative myocardial perfusion assessment. In order to achieve this aim, the study team will compare heart scan results from a computed tomography (CT) Myocardial Perfusion Imaging (CT-MPI) scan and CT-Fractional Flow Reserve (FFR) with the actual standard clinical care represented by a PET Myocardial Perfusion Imaging (PET-MPI) study.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
20
Patients with suspected CAD who are referred to a clinical PET-MPI will undergo the standard clinical protocol applied in the Emory Nuclear Medicine department.
For the CT-MPI, dynamic volume CT myocardial perfusion applying the "dynamic shuttle" mode will be used to rapidly cover the entire cardiac anatomy during infusion of a contrast medium bolus for monitoring bolus passage through the left ventricular myocardium. The "dynamic shuttle" mode consists of an image acquisition during rapid, yet smooth back-and-forth movement of the CT scanner table, so that contrast media bolus passage can be evaluated within the entire left ventricle in a time-resolved fashion. This scan acquisition will be performed during pharmacologically induced stress and during rest conditions. CT-MPI studies will be contrast medium enhanced by 50-70 ml of iodinated contrast agent, administered at a flow rate of 5 mL/s. The CT examinations are scheduled within 90 days of the standard clinical PET examination.
Emory University Hospital
Atlanta, Georgia, United States
Myocardial Blood Flow
The absolute quantification of myocardial perfusion between CT-MPI and PET-MPI is compared. Myocardial perfusion is quantified using appropriate tracer kinetic models resulting myocardial blood flow mL/g/min.
Time frame: Day of PET-MPI Scan, and Day of CT-MPI and CT-FFR Scans (up to 90 days)
Coronary Flow Per CT-FFR
Coronary flow is measured using the CT-FFR calculation with the CCTA scans. CT-FFR measures blood flow through coronary arteries and is used clinically to quantify the severity of CAD to determine further interventions. CT-FFR is the ratio between the blood flow (BF) in a diseased artery and a normal artery. Clinically, the CT-FFR calculation is only useful in patients with intermediate stenosis because stenosis below intermediate results in a value that is near zero and the calculation cannot be performed when stenosis is complete. The normal range for CT-FFR is greater than 0.80, values of 0.76 to 0.80 are borderline while values of 0.75 or less are associated with a high likelihood of reduced blood flow (ischemia).
Time frame: Day of CT-MPI and CCTA scans
Sensitivity of Myocardial Perfusion Abnormalities Diagnosis
The accuracy of detection of myocardial perfusion abnormalities is compared between PET-MPI, CT-MPI, CCTA, and CT-FFR approach. Diagnostic accuracy using CT-MPI, CCTA and CT-FFR is calculated as sensitivity (true positives) with PET as the reference standard.
Time frame: Day 1 (day of scans)
Specificity of Myocardial Perfusion Abnormalities Diagnosis
The accuracy of detection of myocardial perfusion abnormalities is compared between PET-MPI, CT-MPI, CCTA, and CT-FFR approach. Diagnostic accuracy using CT-MPI, CCTA and CT-FFR is calculated as specificity (true negatives) with PET as the reference standard.
Time frame: Day 1 (day of scans)
Area Under the Curve (AUC) for Detection of Myocardial Perfusion Abnormalities
The accuracy of detection of myocardial perfusion abnormalities is compared between PET-MPI, CT-MPI, CCTA, and CT-FFR approach. Diagnostic accuracy using CT-MPI, CCTA and CT-FFR is calculated as overall AUC with PET as the reference standard. The AUC examines the overall accuracy of a diagnostic test. Higher AUC indicates greater accuracy in detecting myocardial perfusion abnormalities with 1.0 being 100% accurate. An AUC value of 0.5 indicates that the test is as accurate as random chance.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Coronary CT angiography (CCTA) will be performed for delineation of the coronary arteries, detection of potential coronary stenosis and FFR calculation. CCTA will be performed at rest following administration of intravenous contrast agent (50-70 mL of iodinated contrast material at a flow rate of 4-5 mL/s). A total radiation dose of approximately 8 millisievert (mSv) has expected to be administered with the stress/rest protocol to the patient. The total amount of contrast agent will not exceed 140 ml. The CT examinations are scheduled within 90 days of the standard clinical PET examination.
Pharmacological stress testing for the CT-MPI scan will be performed with a single injection of 0.4 mg of regadenoson (Lexiscan).
Time frame: Day 1 (day of scans)
Sensitivity of Coronary Stenosis Diagnosis
The accuracy of detection of coronary stenosis is compared between PET-MPI, CT-MPI, and CCTA with CT-FFR approach. Diagnostic accuracy is calculated as sensitivity (true positives) with CCTA as the reference standard.
Time frame: Day 1 (day of scans)
Specificity of Coronary Stenosis Detection
The accuracy of detection of coronary stenosis is compared between PET-MPI, CT-MPI, and CCTA with CT-FFR approach. Diagnostic accuracy is calculated as specificity (true negatives) with CCTA as the reference standard.
Time frame: Day 1 (day of scans)
Area Under the Curve for Detection of Coronary Stenosis
The accuracy of detection of coronary stenosis is compared between PET-MPI, CT-MPI, and CCTA with CT-FFR approach. Diagnostic accuracy is calculated as overall AUC with CCTA as the reference standard. The AUC examines the overall accuracy of a diagnostic test. Higher AUC indicates greater accuracy in detecting coronary stenosis with 1.0 being 100% accurate. An AUC value of 0.5 indicates that the test is as accurate as random chance.
Time frame: Day 1 (day of scans)