Quantification of Myocardial Blood Flow Using Dynamic PET/CTA Fused Imagery

Summary

This observational prospective clinical study is to develop software tools to fuse coronary anatomy data obtained from CT coronary angiography with dynamic PET data to noninvasively measure absolute myocardial blood flow, flow reserve and relative flow reserve across specific coronary lesions. Results will be compared to those obtained invasively in the catheterization laboratory.

Conditions

• Coronary Artery Disease

Interventions

PROCEDURE

Invasive Cardiac Catheterization (ICA)

Invasive functional measurements will be performed to assess the functional significance of specific lesions by means of FFR and CFR, and to test the presence of microvascular disease by means of IMR in all vessels for which the procedures are feasible. In summary, a 5- to 7-F guide catheter without side holes is used to engage the coronary artery and a pressure-temperature sensor-tipped guidewire introduced. The pressure sensor is positioned at the distal segment of a target vessel, and intracoronary nitroglycerine (100-200 mg) administered before each measurement. The best systolic and diastolic phase (located between 30-50%, and 60-75% of the cardiac cycle) will be selected for successive processing as it allows a relative motion free visualization of the main vessels and the myocardium.

PROCEDURE

Coronary Computed Tomographic Angiogram (CCTA)

Fasting patients will undergo a test for coronary calcium by CT; calcium scoring analysis will be done post image data acquisition using the manufacturer's software. Nitroglycerine will be administered in all patients (sublingual administration prior to CCTA initiation). CT acquisitions will be prospectively ECG-gated (30-80% of the cardiac cycle). The acquisition begins with a scout scan to identify the borders of the heart to minimize the field of view and exposure to the patient. A bolus of 60 mL nonionic contrast agent is then injected followed by 60 mL of saline at a rate of 4 mL/s to enhance signal from coronary arteries and blood chambers. In case of irregular heart rate, beta-blockers can be provided to keep optimal heart rate \~65-70 bpm. Trans-axial images are reconstructed by means of a filtered back-projection algorithm.

PROCEDURE

Dynamic Cardiac Positron Emission Tomography (dPET)

Patients will be asked to fast for 24 hours prior to the test. Before the resting perfusion phase, a single low-dose CT-based transmission scan is acquired for attenuation correction (AC) of all subsequent acquisitions. AC-CT images are automatically registered to the perfusion images, visually verified and manually corrected if necessary. Resting perfusion imaging started with the intravenous injection of a single bolus of 82Rb. Pharmacological stress imaging is obtained after adenosine infusion (140 μg/kg/min) through a peripheral vein, followed by a second dose of 82Rb. Image reconstruction is achieved by means of ordered subset expectation maximization (OSEM) iterative method. The hemodynamic responses to rest/stress tests are collected in terms of mean heart rate, mean blood systolic pressures and diastolic at rest and stress. Dynamic, gated and ungated trans-axial reconstructions are saved in DICOM format for further analysis and processing.

Sponsors & Collaborators

• Samsung Medical Center

  collaborator OTHER

• Seoul National University

  collaborator OTHER

• Chonnam National University Hospital

  collaborator OTHER

• National Heart, Lung, and Blood Institute (NHLBI)

  collaborator NIH

• Emory University

  lead OTHER

Principal Investigators

• Marina Piccinelli, PhD · Emory University

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-11-01

Primary Completion

2023-06-30

Completion

2023-06-30

Countries

• United States
• South Korea

Study Locations