Organ-Specific Perfusion Response to Adenosine as Measured Using Total-Body PET.

Area of Science:

• Nuclear Medicine
• Cardiovascular Imaging
• Pharmacology

Background:

• Adenosine is a standard pharmacologic stress agent for myocardial perfusion imaging.
• Its effects on organ perfusion beyond the heart are not well-characterized.

Purpose of the Study:

• To investigate the organ-specific effects of adenosine on tissue perfusion.
• To utilize a long-axial-field-of-view (LAFOV) PET scanner for comprehensive organ imaging.

Main Methods:

• Ninety-one patients with suspected coronary artery disease underwent [15O]H2O LAFOV PET perfusion imaging at rest and during adenosine stress.
• An open-source total-body pipeline with CT-based segmentation was used for organ analysis.
• Absolute perfusion values were quantified for multiple organs.

Main Results:

• Adenosine significantly increased myocardial blood flow (1.01 to 3.47 mL/min/g).
• Liver (1.10 to 3.32), duodenum (0.37 to 0.53), and colon (0.09 to 0.13 mL/min/mL) perfusion increased.
• Brain (0.43 to 0.32), kidneys (0.87 to 0.65), and spleen (1.11 to 0.31 mL/min/mL) perfusion decreased, with spleen showing a 71% reduction.

Conclusions:

• Adenosine elicits distinct, organ-specific perfusion responses.
• While increasing cardiac and splanchnic perfusion, adenosine reduces perfusion in the brain, kidneys, and spleen.