Perfusion/Metabolic Functional Magnetic Resonance Imaging Technologies And Their Applications

G-load is existed extensively in flight processes, such as pulling up, subducting, turning andhovering during flying. Visual functions are commonly impaired and pilots may suffer from blurredvision, grey vision, black vision and other symptoms when they experience G-load. If pilots met withshort-term serious G-load, they would be unconsciousness and disability of operations because of theshortage of oxygen in brain, which would lead to serious aviation accidents. If pilots met withlong-term G-load, the brain blood would be redistributed and metabolism would be altered if brain isusually in short of oxygen supply. Brain functions, such as vision, memory and attention, will beimpaired. Hence, it is of great importance to monitor cerebral perfusion and oxygen metabolism ofpilots, which can promote the aviation safety.In this thesis, cerebral blood flow (CBF) and cerebral oxygen metabolic rate (CMRO2) weremeasured based on perfusion and metabolic functional magnetic resonance imaging technologies.Regional CBF was quantified by two typical arterial spin labeling (ASL) techniques. RegionalCMRO2was measured by combing ASL and susceptibility weighted imaging (SWI) technique.Firstly, pulsed arterial spin labeling technique (PASL) was applied to quantify regional CBF.Perfusion values were analyzed for each brain region based on region of interest and voxel; Secondly,pseudo continuous arterial spin labeling technique (pCASL) was used to quantify regional CBF andthe reproducibilities of PASL and pCASL were compared to show their robustnesses. Finally, ASLand SWI techniques were combined to quantify regional CMRO2.Experimental results showed that both PASL and pCASL techniques were able to quantifyregional CBF which were consisted with previous reports. Perfusion values of default brain networkwere significantly higher than that of the whole brain. CBF in gray matter was within the rang ofvalues reported by previously literatures. The reproducibility of pCASL was significantly higher thanthat of PASL, indicating that pCASL was of more potentials in clinical applications. CMRO2quantified by ASL and SWI techniques were consisted with previous reports, supporting that ourmethod was reliable for the measurement of CMRO2. In conclusion, perfusion and metabolicfunctional magnetic resonance imaging techniques can be applied to noninvasively monitor brainfunctions of pilots in future.