Purpose. To investigate the use of ASL in evaluation of neuronal activation in cognitive task, cerebral perfusion and cerebrovascular reactivity (R) in healthy subjects.

Materials and methods. 12 healthy subjects were examined (age 58 [57;59]) on Siemens Verio 3.0T scanner with protocol: T2, FLAIR, T1 mpr, Т2*-GRE (fMRI BOLD), PASL (fMRI ASL). Data describing the executive function networks were obtained during simple block Stroop test. Cerebrovascular reactivity was determined using vasodilatation gas (inhalation of СО2-6%, О2-21%, N2-73%). We analyzed data by comparing ASL-based and BOLD-based activation maps, and calculating cerebral blood flow (CBF) in rest and active periods in normo- and hypercapnic conditions - CBFrest(HC), CBFactive(HC), CBFrest, CBFactive. R(%)=(CBFrestHC-CBFrestNC)/CBFrestNCх100%. We used xjView9.0, ASLtbx with SPM8; ITK-SNAP.

Results. FMRI ASL demonstrated activation of the same areas as on fMRI BOLD. They included executive and salience networks components. CBFrest(NC) was increased in these areas vs reference areas. CBFactive(NC) was higher than CBFrest(NC). CBFactive(HC) measurements were the highest (up to 97.6ml/100g/min in supplementary motor area). Decrease of CBFactive(HC) was shown only in anterior cingulum. R was within 11-21% in all areas.

Discussion. FMRI ASL is comparable to FMRI BOLD in assessment of brain executive function. Quantitative CBF measurement in activated areas allows to determine their role in cognitive task and to evaluate whether R is adequate to perform the task.

Conclusion. ASL provides both functional and perfusion data without any contrast agent. It makes ASL a perspective tool in the assessment of neurovascular interaction in cognitive dysfunction.