Effects Of Different Regions Of Interest On Cerebral Perfusion Of 3D-ASL

Objective Region of interes regions of interest(ROI)of the 3-dimensional arterial spin labeling(3D-pulsed continuous Arterial spin Labeling,3D-ASL)were delineated by different methods to explore the effect of ROI delineated by different methods on 3D-ASL perfusion measurements.Materials and Methods Brain 3D-ASL perfusion samples scanned in the Affiliated Hospital of Qingdao University from September 2020 to November 2021,By magnetic resonance(Magnetic Resonance Imaging,MRI)for the sequence scanning,A total of 100 samples were successfully included in the study,The scan sequence includes routine T1-weighted imaging(T1 weighted imaging,T1WI),T2-weighted imaging(T2 weighted imaging,T2WI),T2 FLAIR sequence,diffusion-weighted imaging(diffusion weighted imaging,DWI)Sequence and the 3D-ASL sequence.Raw data of brain perfusion were obtained by3D-ASL sequence scanning in MR and analyzed by the 3D-ASL program in the GE post-processing workstation to obtain whole-brain blood flow(cerebral blood flow,CBF)perfusion maps for each volunteer.In this study,the differences of CBF measurements between left and right cortical areas and white matter areas were compared;the cortical areas were divided according to ASPECT stroke CT score,and areas M4,M5 and M6 above the core level(2cm at the core level)were selected.The left ROI area is outlined with full coverage to measure the CBF value of M4-6 area as the actual reference value,and the right side of the mirror area is used as the control side,including the ROI area of the right side.Right ROI range size: 1 gyri + 1 adjacent sulcus as 1 reference width unit,small ROI value range is defined as no more than 1 width unit(ROI less than 1 gyri + adjacent sulcus);moderate RIO is defined as more than 1 but not more than 3 width units(i.e.,ROI contains at least 1 gyrus + adjacent furci,but not more than 3 gyri + adjacent sulci);while large ROI is defined as more than 3 width units(that is,ROI size contains more than 3 gyri + adjacent sulci);The white matter area of the brain was selected to outline the ROI,and in the right area,small,medium and large specifications were used for CBF numerical easurement.ROI delineation was performed with three CBF data measurements as described above,and the triplicate was averaged.All were outlined with three CBF data measurements and then averaged.The ggpolt2 toolkit of R language software was used to obtain the probability density map of the CBF values formed from four different ROI delineation in cerebral cortical area(M4-6 area)and cerebral white matter region,respectively,and the probability density map of the difference between the CBF value of small ROI,medium ROI,ROI and large ROI and the CBF value of the left full coverage R O I.Using one-way ANOVA of SPSS 26.0 statistical software,the CBF values of right small ROI,medium ROI and large ROI and the CBF value of left full coverage ROI were processed by one-way ANOVA,obtaining the line plot of cerebral cortex and white matter.Results(1)In the cortical area,the CBF value of the right small ROI and middle ROI varied significantly from the CBF value of the left full coverage ROI,statistically significant(P<0.05),and the CBF value of the large ROI was not very different from the CBF value of the left full coverage ROI.(2)In the brain white matter region,the CBF values of the right small ROI,medium ROI,and large ROI were not significantly different from the CBF value of the left full coverage ROI(P> 0.05).Conclusions Taking the CBF measured by the left full coverage ROI as the actual reference standard,the smaller the ROI in the cortical area,the greater the deviation of the CBF value,and the closer the ROI,the closer the ROI in the white matter area has no effect on the CBF value.The size of the selected ROI area of ASL cerebral perfusion has a great impact on the CBF measurements in cortical areas,so the largest ROI should be selected when measuring CBF in cortical areas to obtain the as accurate CBF measurements as possible.