CFR and FFR assessment with PET and CTA: strengths and limitations

Area of Science:

• Cardiovascular Imaging
• Radiology
• Computational Fluid Dynamics

Background:

• Positron emission tomography myocardial perfusion imaging (PET-MPI) offers high accuracy and prognostic value for diagnosing coronary artery disease.
• PET-MPI enables quantitative assessment of myocardial blood flow (MBF) and calculation of coronary flow reserve (CFR)/myocardial flow reserve (MFR).
• Coronary computed tomography angiography (CTA) accurately detects coronary stenoses but tends to overestimate severity and cannot assess physiologic significance.

Purpose of the Study:

• To review the assessment of coronary flow reserve (CFR)/myocardial flow reserve (MFR) using PET-MPI.
• To review the assessment of lesion significance using CT-derived fractional flow reserve (FFRCT) derived from CTA.
• To highlight advancements in non-invasive hemodynamic assessment of coronary artery disease.

Main Methods:

• Review of existing literature on PET-MPI for CFR/MFR quantification.
• Review of advancements in computational fluid dynamics and image-based modeling for calculating non-invasive FFRCT from CTA.
• Comparison of PET-MPI and CT-based hemodynamic assessments.

Main Results:

• PET-MPI provides accurate quantitative assessment of myocardial blood flow and coronary flow reserve.
• CT-derived fractional flow reserve (FFRCT) can be calculated from standard CTA without additional imaging or interventions.
• FFRCT overcomes limitations of CTA in assessing the physiologic significance of coronary stenoses.

Conclusions:

• Both PET-MPI and CT-based FFRCT are valuable non-invasive tools for evaluating coronary artery disease.
• These techniques offer complementary information for diagnosing and managing patients with suspected or known coronary artery disease.
• Advancements in imaging and modeling are enhancing the non-invasive assessment of coronary hemodynamics.