The Application Of Magnetic Resonance Perfusion Weighted Imaging In Moyamoya Disease

BackgroundMoyamoya disease(MMD)is a kind of cerebrovascular disease characterized by chronic progressive stenosis or occlusion at the end of internal carotid artery and/or the beginning of anterior cerebral artery and middle cerebral artery,and abnormal vascular network at the base of skull.Because of the formation of abnormal vascular network at the base of skull like smoke,MMD becomes a moyamoya disease.The occurrence of moyamoya disease is concealed,but it develops slowly and progressively.When found,it often causes serious neurological dysfunction,seriously affects the quality of life of patients,and brings heavy financial burden to patients' families.Although CT angiography(CTA),digital subtraction angiography(DSA)and magnetic resonance angiography(MRA)can show stenosis or occlusion of blood vessels,the clinical symptoms often do not correspond to the degree of stenosis or occlusion of blood vessels due to the presence of collateral circulation.Magnetic resonance perfusion weighted imaging(PWI)is a function is developing rapidly in recent years imaging method,it can be in all the parameters on the basis of numerical reflect the hemodynamic changes in brain tissue to evaluate the perfusion in brain tissue,so as to evaluate the patient's condition,and they had no ionizing radiation,high spatial resolution,simple operation,gradually become widely clinical application of perfusion imaging methods.ObjectiveThe hemodynamic changes of patients with moyamoya disease were evaluated by magnetic resonance perfusion weighted imaging,and the application value of magnetic resonance perfusion weighted imaging in the evaluation of moyamoya disease was discussed.Methods1.PWI perfusion images of 56 MMD patients examined in the MRI department of our hospital and confirmed by DSA/MRA from July 2017 to September 2018 were collected,including 39 patients with typical MMD and 17 patients with unilateral MMD.PWI perfusion images of 20 healthy patients with normal MRA and MRI were selected as the control group.2.All the subjects of the study used the German Siemens Verio 3.0T superconducting magnetic resonance scanner,and obtained CBV,CBF,MTT and TTP images after post-processing with MR Perfusion software in the Siemens post-processing workstation.3.The double blind method was used to analyze the image qualitatively and quantitatively.Qualitative analysis: observe whether there is perfusion abnormality in CBV,CBF,MTT and TTP.Quantitative analysis: according to the TTP image as the standard,the area of interest(ROI)was selected in the areas with abnormal perfusion in the blood supply area of the middle cerebral artery and anterior cerebral artery,CBV,CBF,MTT and TTP were measured,and then the corresponding parameter values were measured by the mirror image method.For the normal control group,the values of each parameter were measured at the same position and level.In this study,the ipsilateral cerebellum was used as a reference to conduct standardized processing for each parameter value,and rCBV,rCBF,rMTT and rTTP were obtained,respectively.4.Then,statistical methods were used to compare and analyze the differences in rCBV,rCBF,rMTT and rTTP between the bilateral moyamoya disease group and the normal control group,the unilateral moyamoya disease group and the healthy side group,and the unilateral moyamoya disease group and the normal control group,respectively.Paired t test was used for the comparison between the two groups,and P<0.05 was statistically significant.Results1.There were no abnormal perfusion in CBV,CBF,MTT and TTP images in 20 normal control groups.The number of cases with abnormal perfusion of CBV,CBF,MTT and TTP in MMD patients were 27 cases,33 cases,49 cases and 56 cases.The abnormal perfusion rates of CBV,CBF,MTT and TTP were 48.2%,58.9%,87.5% and 100%.The sensitivity of TTP and MTT was significantly better than that of CBV and CBF.2.rMTT and rTTP in bilateral moyamoya disease group were longer than those in normal control group,rCBF decreased,rMTT,rTTP and rCBF had statistical significance(P< 0.05),rCBV was slightly lower than that in normal control group,but there was no statistical difference(P> 0.05).The rCBV and rCBF of unilateral moyamoya disease side decreased,rMTT and rTTP prolonged,and rCBV,rCBF,rMTT and rTTP of unilateral moyamoya disease side had statistical significance(P< 0.05).There was no significant difference in rCBV,rCBF,rMTT and rTTP between unilateral moyamoya disease healthy side and normal control group(P> 0.05).Conclusion1.Hemodynamic changes of moyamoya disease often show that CBF decreases in varying degrees,MTT and TTP prolongs,and MTT and TTP are more sensitive than CBV and CBF.2.MR perfusion imaging can clearly show the location,extent and degree of ischemia of perfusion anomalies,which is of great value for the evaluation of moyamoya disease.