Quantitative and qualitative comparison of Rubidium-82 and Oxygen-15 water cardiac PET

Area of Science:

• Cardiology
• Nuclear Medicine
• Medical Imaging

Background:

• Tracer characteristics can affect the interpretation of myocardial perfusion imaging (MPI).
• Comparing different tracers is crucial for optimizing diagnostic accuracy in cardiology.
• Understanding these differences aids in selecting the most effective MPI tracer for patients with known coronary artery disease (CAD).

Purpose of the Study:

• To compare the interpretation of MPI using a low-extraction retention tracer (⁸²Rb) and a high-extraction non-retention tracer (¹⁵O-water).
• To evaluate the agreement in diagnosing regional and global ischemia in patients with known CAD.
• To assess quantitative measures of myocardial perfusion between the two tracers.

Main Methods:

• Thirty-nine patients with known CAD underwent rest and stress MPI with both ⁸²Rb and ¹⁵O-water.
• Experienced readers provided blinded consensus reads of all MPI studies.
• Regional and global quantitative measures of myocardial perfusion were compared.

Main Results:

• There was 74% agreement for regional reversible ischemia and 82% agreement for regional irreversible ischemia between ⁸²Rb and ¹⁵O-water MPI.
• ¹⁵O-water MPI identified significantly more cases of global disease (p=0.03).
• Correlation between myocardial blood flow measurements showed R²=0.78 with wide limits of agreement.

Conclusions:

• Agreement between ⁸²Rb and ¹⁵O-water MPI readings was good in patients with known CAD.
• No significant differences were found in identifying reversible or irreversible ischemia between the tracers.
• ¹⁵O-water MPI demonstrated a higher detection rate for suspected global disease in this cohort.