ABSTRACT
Objective To study the value of three-dimensional pseudo-continuous arterial spin labeling(3D pCASL) for estimating collateral flow after middle cerebral artery(MCA) stenosis.Methods 3D pCASL was performed in 28 cases of negative diffusion weighted imaging(DWI) patients with MCA stenosis for estimating collateral vessels formation.The post-labeling delay(PLD) of 3D pCASL was set to 1.5 s and 2.5 s.The cerebral blood flow (CBF) of 3D pCASL with two PLD was calculated by AW workstation respectively.Nineteen normal persons were regarded as the control group.The 95% confidence interval of the ratio of left/right side of CBF of control group was set as reference value.The characteristic of the ratio of stenosed/contralateral side of CBF was analyzed.The characteristics of collateral flow was investigated with digital subtraction angiography(DSA).Results Abnormal perfusion was found in 28 patiens.Two types of abnormal perfusion were found, including typeⅠ: rCBF(PLD=1.5 s) decreased,rCBF(PLD=2.5 s) was normal (n=16);typeⅡ:rCBF(PLD=1.5 s) decreased,rCBF(PLD=2.5s) decreased (n=12).On brain DSA, abundant of collateral flow supply was found in 16 patients with typeⅠabnormal perfusion,whereas deficiency of collateral flow supply was found in 12 patients with typeⅡ.Conclusion 3D pCASL with two PLDs may provide important reference value for estimating collateral flow after middle cerebral artery stenosis.
ABSTRACT
Objective To investigate the clinical value of susceptibility weighted imaging (SWI)combined with three dimensional pseudo continuous arterial spin labeling (3D-PCASL)on the prognosis analysis of acute cerebral infarction.Methods Thirty cases with acute cerebral infarction (< 72 h)underwent conventional MRI,MRA,3D-PCASL and SWI.NIHSS scores were performed at the time of examination and 3 months later.The correlation between the collateral blood vessels,regional cerebral blood flow (rCBF)detected by combination of SWI and 3D-PCASL with clinical prognosis were analyzed.Results Twenty-three cases showed collateral blood vessels in the lesions with 1 grade in 14,and 2 grade in 9.The average rCBFs in grade 0,1,2 infarction areas were (22.69±11.94)mL·100 g-1 ·min-1 ,(25.10±16.55)mL·100 g-1 ·min-1 and (33.04±24.24)mL·100 g-1 ·min-1 ,respectively.Collateral blood vessels,rCBF were positive correlated with the NIHSS scores (r=0.989,P< 0.01).18 cases showed multiple vessels around the lesions. The average rCBFs in the infarction area with or not with periphery collateral blood vessles were (28.33±24.24)mL·100 g-1 ·min-1 and (22.69±11.94)mL·100 g-1 ·min-1 ,respectively.There was a positive correlation between rCBF and NIHSS scores (r=0.897,P<0.01). Of 30 cases of acute cerebral infarction,the average CBFs in the infarct areas and the contralateral mirror areas were (26.92±18.22)mL·100 g-1 · min-1 and (34.22±12.37)mL·100 g-1 ·min-1 .There was significant difference (t=8.093,P<0.01).Conclusion The combination of SWI and 3D-PCASL can display the collateral blood vessels in the lesions and soft meninges,and provide the quantitative analysis of rCBF,which has important clinical significance for prediction of the prognosis of acute cerebral infarction.