Preliminary Evaluation Of DSA Parametric Imaging In The Changes Of Cerebral Perfusion And Microcirculation Of Pre-and Post-stenting In Carotid Artery Stenosis

Objectives: To evaluate cerebral perfusion and hemodynamics of pre- and post-arterial stenting for carotid artery stenosis by DSA parametric imaging.Methods: 15 patients(male 13,female 2) with symptomatic carotid artery stenosis underwent the carotid stenting(CAS) were chosen,All of the patients were mono-carotid artery stenosis,the degree of stenosis>75%. The machines used in this study were INNVA4100 and LF high-pressure syringe.The patients lied on the bed of the machine and the heads were fixed with headframe, made the canthomeatal lines perpendicular to the bed of the machine.By injiecting 1% dolicaine to local anesthesia, the patients were kept conscious-sedation with a small amount of Diazepam.The digital subtractional images of diplo-carotid arteries and one side of vertebral arteries were acquired before stenting.During the imaging the patients were told to keep the head static and not to do the action of swallowing.Before stenting, the blood pressure,the heart rate and the respiration rate of the patients were recorded.After stenting,the the blood pressure,heart rate and the respiration rate of the patients were observed,if there was the degression of the blood pressure and the heart rate,0.5mg Atropine was injiected,if there was the spasmodism of the vessels, 30mg Papaverine was injected.Images were not acquired until the blood pressure,the heart rate and the respiration rate of the patients recovered the levels of pre-operation,the spasmodism of the vessels was eliminated.The location of the catheter and the parameters of the images of pre-and post-operation were at equal.Then the images were processed by special software in personal computer(PC).The reign of interesting(ROI)were located in brain,feeding arteries and sinus venosuses separately,then with the soft ware,the time- gray scale curves were gained and we could get the parameters of brains, feeding arteries and sinus venosuses:the parameters were peak value (PV),mean transit time (MTT),time to peak (TP),time of appearance to the peak ,the max slope rate of the curve and the time of cerebral cirulation.Results: 1 Parameters of the side of stenosis.First, changes of the parameters of the brain:after stenting,the PV and the max slope rate of the curve increased,but there was no difference in the time of appearance to the peak before and after operation;TP and MTT of pre-operation exceeded that of post-operation.Second, changes of the parameters of feeding arteries:PV and the the max slope rate of the curve increased ,but there was no difference in the time of appearance to the peak before and after operation;TP of pre-operation exceeded that of post-operation.Third,changes of the parameters of sinus venosuses:PV,time of appearance to the peak and the the max slope rate of the curve increased after stenting,but there was no difference of TP before and after operation.Time of cerebral circulation decreased after stenting. 2 Parameters of the side of contralateral. First,changes of the parameters of the brain:after stenting,PV,TP,MTTand the time of appearance to the peak increased,but there was no diference in the max slope rate of the curve.Second, changes of the parameters of feeding arteries:PV,time of appearance to the peak and TP increased after stenting,while the max slope rate of the curve decreased after stenting.Third,changes of the parameters of sinus venosuses:PV,the time of appearance to the peak and TP increased after stenting,while the max slope rate of the curve decreased after stenting.Time of cerebral circulation increased after stenting.3 Parameters of post-circulation.First,changes of the parameters of the brain:TP,MTT and time of appearance to the peak increased after stenting,but the max slope rate of the curve decreased after stenting,there was no difference of PV before and after operation.Second,changes of the parameters of feeding arteries:time of appearance to the peak and TP increased after stenting,but there was no deference of PV and the max slope rate of the curve before and after operation.Third,changes of the parameters of sinus venosuses:PV and the max slope rate of the curve decreased after stenting,while time of appearance to the peak and TP increased after stenting. Time of cerebral circulation increased after stenting.4 Comparison of the side of stenosis and the contralateral of before operation.First,differences in the parameters of the brain pre-operation: parameters of TP,time of appearance to the peak and MTT of the side of stenosis exceeded that of the contralateral, the parameters of PV and the max slope rate of the curve of the side of stenosis were smaller than those of the contralateral.Second,differences in the parameters of feeding arteries before operation:the parameters of TP and time of appearance to the peak the side of stenosis exceeded those of the contralateral, the parameters of the max slope rate of the curve of the side of stenosis were smaller than those of the contralateral.There was no difference of PV.Third,differences in the parameters of sinus venosuses:the parameters of TP and time of appearance to the peak of the side of stenosis exceeded those of the contralateral,the parameters PV and the max slope rate of the curve of the side of stenosis were smaller than those of the contralateral.While time of cerebral circulation of the side of stenosis exceeded that of the contralateral.5 Comparison of the side of stenosis and the contralateral of post-operation.First, differences of the parameters of the brain before operation:the parameters of MTT,TP and time of appearance to the peak of side of stenosis were smaller than those of the contralateral,There was no difference in PV and the max slope rate of the curve.Second, differences of the parameters of feeding arteries before operation:the parameters of TP and time of appearance to the peak of the side of stenosis were smaller than those of the contralateral,There was no difference in PV and the max slope rate of the curve. Third, differences of the parameters in sinus venosuses:the parameter of the max slope rate of the curve the side of stenosis was smaller than that of the contralateral, There was no difference of PV,TP and time of appearance to the peak.Time of cerebral circulation of the side of stenosis was smaller than that of the contralateral.Conclusions:1 DSA parametric imaging could be used to evaluate the changes of cerebral perfusion and hemodynamics before and after arterial stenting,the change of cerebral perfusion was reflected by PV,the change of hemodynamics was reflected by MTT and time of cerebral circulation.we could obtain digital subtraction images directly.From the digital subtraction images,we could observe the flow of the cerebral blood integraly,this character of the DSA was superior to other medical imaging epuipments.2 The software used in this study was specially made by us,it may be used in personal computer.The conclusions of this study acquired by this software were similar to the results gotten by other medical imaging equipment,so the exploitation and the preliminary use of this software was successful.