Abstract
Introduction/Purpose –Cerebral arterial blood flow contributes directly to stroke, plays a role in aneurysm progression, and has increasingly been linked to neurological disease. The purpose of this research was to establish baselines for cerebral flow in various arteries of healthy individuals, which can be used as controls when studying cerebrovascular disease.

Materials/Methods – Non‐contrast 4D Flow MRI of the brain was acquired using a Siemens 3T Magnetom Vida scanner in 9 volunteers (4 Male, 5 Female), mean age 33 ± 11 years. A compressed sensing protocol (R=7.7) was used to accelerate ECG‐gated image acquisition, with a 1.4 mm3 voxel size, and 15‐25 cardiac phases. Total image acquisition time was approximately 10‐15 minutes. Flow was measured in the major intracranial arteries, including the left and right internal carotid (ICA), anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA). Flow was also measured in the basilar artery (BA) and vertebral arteries (VA). 4D flow data were analyzed using Tempus Pixel (Tempus, IL). Student’s t‐test was used for statistical analysis.

Results – Time‐averaged flow values were calculated for each volunteer and averaged across the cohort to provide the following values (mL/min right/left): ICA 262 ± 76, 292 ± 78; ACA 75 ± 30, 98 ± 41; MCA 163 ± 44, 152 ± 56; PCA 77 ± 17, 67 ± 14; VA 82 ± 30, 138 ± 38; BA 188 ± 30. Average total cerebral blood flow (TCBF) was 742 mL/min, calculated by adding ICA and BA values. This value corresponds well with earlier 4D flow measurements collected without compressed sensing. Average flow only differed between the left and right vessel at the VA (p < 0.01). This likely reflects the often‐noted higher frequency of people with left‐dominant VA. Finally, when we split our cohort at age 30, we observed higher rates of flow in the younger group in the ICA (342±50 vs. 224±45) and MCA (196±44 vs. 126±27) (p < 0.01).

Conclusion – 4D Flow MRI enables the non‐invasive measurement of blood flow, but its usage in the brain remains relatively uncommon in clinical practice. We implemented a compressed sensing protocol for faster acquisition and measured cerebral blood flow in a healthy cohort. Our findings were consistent with earlier reported values for this age range and support our investigation of cerebrovascular disease.

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