Preoperative And Postoperative Study Of Moyamoya Disease Based On Sparse TOF-MRA And The Application Of Combined Revascularization Rank Score

Objective:To compare the image quality and diagnosis potential between conventional three-dimensional time-of-flight magnetic resonance angiography（c TOF-MRA）and TOF MRA with sparse undersampling and iterative reconstruction（s TOF-MRA）in patients with moyamoya disease（MMD）.To verify the relationship between combined revascularization rank score with improvement degree of clinical symptoms,improvement degree of cerebral blood perfusion and the degree of disappearance of abnormal MRI imaging signs.To set up binary logistic regression model and find the factors that have impact on combined revascularization rank score of patients with moyamoya disease after combined revascularization surgery.Materials and Methods:This study included 108 patients with MMD,43 males,age between 6-69 years,and 68 patients taken combined revascularization surgery.All patients underwent c TOF-MRA,s TOF-MRA,FLAIR-MRI、SWI-MRI and high resolution-MRI（HR-MRI）simultaneously on a 3.0 T MR scanner before operation,early period of post-operation and long term of post-operation.All patients underwent cerebral digital subtraction angiography（DSA）and cerebral CT perfusion test before operation,early period of post-operation and long term of post-operation.Modified Houkin’s grading system（MRA score）was applied to evaluate the main intracranial arteries.While,MMVs were assessed by MMVs area score and MMVs quality score.TOF criteria was the diagnosis criteria of moyamoya disease that based on the number of high signal intensity areas in the bilateral basal ganglion on MRA source images.Combined revascularization rank score was the sum of Matsushima grade and donor vascular patency score,which was used to evaluate the improvement degree of cerebral blood perfusion after combined revascularization surgery.The CTP stage of preinfarction period and CTP parameters were used to evaluate the cerebral blood perfusion of patients with moyamoya disease.The abnormal MRI imaging signs included Ivy sign,Brush sign and CVS sign.High and low combined revascularization rank score was taken as the dependent variables;the age of patients and the vascular wall characteristics of the superficial temporal artery（STA）of the surgical side on HR-MRI vascular wall imaging were taken as independent variables,and the binary logistic regression analysis was performed.Results:Significant difference was observed between c TOF-MRA and s TOF-MRA on both MRA score and MRA grade（all P<0.001）.And the correlation between DSA Suzuki’s stage and the MRA score of c TOF-MRA was moderate（r_s=0.755;P<0.001）,but a strong correlation between DSA Suzuki’s stage and the MRA score of s TOF-MRA（r_s=0.854;P<0.001）.In addition,the correlation between DSA Suzuki’s stage and the MRA grade of c TOF-MRA was moderate（r_s=0.784;P<0.001）.But the correlation between DSA Suzuki’s stage and the MRA grade of s TOF-MRA was strong（r_s=0.884;P<0.001）.Both MMVs area score and MMVs quality score demonstrated that the MMVs were depicted significantly better on s TOF-MRA than on c TOF-MRA（both P<0.001）.Furthermore,s TOF-MRA showed greater capacity in showing the high signal intensity areas in the basal ganglia compared with c TOF-MRA（P<0.001）.According to the TOF criteria,the diagnostic categories of MMD on s TOF-MRA were significantly better than those on c TOF-MRA（P<0.001）.There was significantly difference of improvement degree of clinical symptoms between combined revascularization rank score 1-2 and 3-4,and between 1-2 and 5-6（P₁,P₂<0.05）;but there was no significant difference between 3-4 and 5-6（P₃=0.676）.And there was no significant difference of improvement degree of clinical symptoms among groups of Matsushima grade（P=0.481）.There was significant difference of all the changed values of CTP stage of preinfarction period,TTP,MTT and CBF among combined revascularization rank score 1-2,3-4 and 5-6（P₁,P₂,P₃<0.05）.There was significant difference of reduced degree of Ivy sign and CVS sign among combined revascularization rank score 1-2,3-4 and 5-6（P₁,P₂,P₃<0.05）.By binary logistic regression analysis,there was statistical significance of the partial regression coefficient of age of patients,the homogenous of STA and inner diameter of STA pre-operation（P=0.017,0.004,0.011）;but there was no statistical difference of the partial regression coefficient of enhancement pattern of STA pre-operation（P=0.215）.Conclusion:Compared with c TOF-MRA,s TOF-MRA had significant advancement not only in detection and delineation of MMVs,but also in the depiction of the main intracranial arteries.Thus,we presumed that s TOF-MRA was a promising technique in the diagnosis and evaluation of MMD for its invasive property compared with DSA and its advantages in the depiction of MMVs and main intracranial arteries over c TOF-MRA.compared with Matsushima grade,combined revascularization rank score can better distinguish the improvement degree of cerebral blood perfusion of patients with moyamoya disease after combined revascularization surgery.In addition,combined revascularization rank score also has a clear distinction on the reduced degree of abnormal MRI imaging signs of patients with moyamoya disease after combined revascularization surgery.The age of patients,the homogenous of STA and inner diameter of STA pre-operation has close relation with combined revascularization rank score.