Myocardial blood flow quantification by Rb-82 cardiac PET/CT: A detailed reproducibility study between two...

Area of Science:

• Nuclear Medicine
• Cardiovascular Imaging
• Quantitative Analysis

Background:

• Accurate myocardial blood flow (MBF) quantification from cardiac PET is crucial for clinical applications.
• Existing software packages for MBF analysis lack comparative concordance studies.
• Reproducibility of MBF measurements is essential for its full clinical potential.

Purpose of the Study:

• To compare the concordance, precision, and bias of two analysis software packages (PMOD and FlowQuant) for myocardial blood flow (MBF) and myocardial flow reserve (MFR) quantification.
• To assess the interchangeability of these software packages in clinical practice.

Main Methods:

• Dynamic Rubidium-82 (Rb-82) PET scans were performed on 51 patients at rest and during adenosine stress.
• MBF and MFR were quantified using PMOD and FlowQuant with the Lortie model and analyzed via a 17-segment model.
• Concordance analysis, including Pearson's correlation (ρ) and Lin's concordance correlation coefficient (ρc), was used to assess precision and bias.

Main Results:

• Excellent precision (ρ=0.97, ρc=0.96) and minimal systematic bias (Cb=0.99) were found for MBF quantification between PMOD and FlowQuant.
• Good precision (ρ=0.83, ρc=0.76) and a slight systematic bias (Cb=0.92) were observed for MFR.
• While PMOD showed slightly higher values at higher MBF/MFR, Bland-Altman plots indicated no significant mean bias on a per-segment basis.

Conclusions:

• Excellent concordance was demonstrated between PMOD and FlowQuant for both MBF and MFR quantification in Rb-82 cardiac PET.
• Despite minor differences at higher values, both software packages can be used interchangeably in routine clinical practice.
• These findings support the reliable use of either software for quantitative cardiac PET analysis.