The Research Value Of Functional Magnetic Resonance Imaging In Parkinson’s Disease

BackgroundParkinson’s disease(PD)is a common neurodegenerative disease,itsetiology has not yet been fully clarified,the pathogenesis is mostlyassociated with the degeneration and loss of dopaminergic neurons in thesubstantia nigra(SN)and the imbalance between the dopamine andacetylcholine neurotransmitter.In recent years,some studies revealsbrain-iron accumulation plays an important role in the pathophysiology ofPD,especially the pars compacta of SN;There have been some changes ofthe microscopic structure and function in the substantia nigra-striatum nervefiber loop,which is significantly decreased in fractional anisotropy(FA)value in diffusion tensor imaging(DTI).Therefore,further studies in PD canmonitor the pathological changes on the iron metabolism of brain tissue,thechanges of the brain-iron in specific parts and DTI parameters,and arevaluable to the clinical diagnosis and early treatment.ObjectiveObserve the structural changes of the extra-corticospinal tract andfrontal white matter in PD using susceptibility-weighted imaging(SWI)andDTI,and investigate the correlation of brain-iron accumulation and DTI parameters with the clinical status,and explore some imaging clues for PD’sdiagnosis.Methods6patients with PD and6age-and sex-matched healthy controlunderwent the routine MR plain scan,SWI and DTI scan.The correctedphase(CP) value of substantia nigra(SN),red nucleus(RN),globuspallidus(GP),putamen(PU),caudate nucleus(CA),thalamus (TH) and frontalwhite matter (FWM) were measured in CP imaging,FA imaging and ADCimaging.All data were analyzed.ResultsSignificant differences were found at the phase shift values betweenPD group and healthy control in SN,RN and PU,while the differences inother regions of interest(ROI) were not found.There were no significantdifferences at the phase shift values in the two sides of PD group and healthycontrol except for the FWM.No correlation between the phase shift valuesin the SN,RN and PU and duration of PD was observed. Also,the phase shiftvalues in the SN,RN and PU was not associated with the Unified Parkinson’sDisease Rating Scale (UPDRS)score.The FA values in SN and PU in the patients with PD decreasedobviously compared with control group (p<0.05).No significant differenceswere observed between PD group and healthy control at other ROI’s FAvalues.No significant differences were observed at FA values and ADC values in the two sides of PD group.No significant differences wereobserved at ADC values between PD group and healthy control.The FAvalues of the SN in PD was closely associated with the duration,but not withthe UPDRS score.There was no obvious correlation between the FA valuesof the PU and duration of PD.Also,no obvious correlation between the FAvalues of the PU and the UPDRS score was observed.The positivecorrelation was observed between the mean phase shift values and the meanFA values in the SN of PD patients.But the mean phase shift values didn’tsignificantly correlate with the mean FA values in the PU.ConclusionsSWI provides a method for evaluating brain-iron deposition in PD.Increasing of iron store concerns with PD’s pathogenesis,but not with thedegree of severity.The FA values is useful to diagnose PD and DTI canoffer some important informations for PD’s pathomechanism and clinicaldiagnosis.