Optimization of temporal sampling for ⁸²rubidium PET myocardial blood flow quantification

Area of Science:

• Nuclear medicine
• Cardiovascular imaging
• Radiopharmaceutical science

Background:

• Suboptimal temporal sampling in dynamic PET myocardial perfusion imaging can lead to biased and variable estimates of myocardial blood flow (MBF) and flow reserve (MFR).
• Accurate quantification of MBF and MFR is crucial for diagnosing and managing cardiovascular diseases.

Purpose of the Study:

• To optimize temporal sampling strategies for dynamic rubidium-82 chloride (⁸²Rb) PET imaging.
• To minimize bias and variability in MBF and MFR estimates derived from myocardial perfusion scans.

Main Methods:

• Dynamic stress/rest ⁸²Rb PET imaging was performed in healthy volunteers and patients.
• Fourier analysis determined optimal sampling intervals (T_S) based on the full width at half maximum (FWHM) of the left ventricular (LV) blood pool time-activity curve (TAC).
• Datasets were reconstructed with varying frame durations for blood and tissue phases, and MBF/MFR were quantified using a compartment model.

Main Results:

• Sampling interval (T_S) increased linearly with input function FWHM.
• Blood phase frame durations of 5 seconds resulted in <5% bias for MBF and MFR.
• Increasing tissue phase frame durations up to 120 seconds yielded <5% bias.

Conclusions:

• A two-phase framing strategy is optimal for dynamic ⁸²Rb PET myocardial perfusion imaging.
• Recommended frame durations are 5 seconds for the blood phase and 120 seconds for the tissue phase.
• This optimized sampling improves the accuracy of MBF and MFR quantification on modern 3D PET systems.