Sex differences in brain perfusion during adenosine stress as measured using total-body positron emission tomography

Abstract Introduction Novel total-body positron emission tomography (PET) scanners offer a unique possibility to simultaneously measure various organ functions in the body. Adenosine is routinely used as a pharmacological vasodilator in myocardial perfusion imaging. Purpose The study aimed to investigate sex differences in brain perfusion at rest and during adenosine stress. Methods A total of 130 patients with suspected coronary artery disease and without prior stroke were prospectively recruited to undergo total-body [15O]H2O PET perfusion imaging at rest and during adenosine stress. The brain and the heart were analysed using organ-specific models. K1-derived absolute perfusion for different brain regions was measured using a single-tissue-compartment model. Comparison of regional brain perfusion between sexes was adjusted with the volume of the regions of interest. k2-derived absolute myocardial perfusion was measured for the heart. Results Myocardial perfusion was significantly lower in males (rest median 0.84 [25th-75th percentiles 0.75–0.94] mL/min/g and stress 2.54 [2.15–2.95] mL/min/g) compared with females (rest 1.13 [0.96–1.30] mL/min/g and stress 3.44 [2.75–3.81] mL/min/g) both at rest (p