Perfusion-weighted MR Imaging In Unilateral Internal Carotid Artery System With Stenosis Or Occlusion And The Application In Interventional Treatment

ObjectiveTo analysis the performance of perfusion-weighted image in internal carotidartery system with stenosis or occlusion.To discuss the application of PWI incerebravescular interventional treatment.Date and Methods1．Patients hospitalized in the Neurology Department of our hospital wasincluded into the study according to the following criteria: those who hadinternal carotid artery ischemia within1week, including cerebral infarction(CI)and transient ischemia attack (TIA); those whose DSA demonstrated theinternal carotid artery or middle cerebral artery stenosis or occlusion on focusside, and no severe internal carotid stenosis on the other side; and those whoseMRI perfusion-weighted image showed corresponding perfusion defects.2. General clinical data was collected from the included patients;3. MRI perfusion-weighted imaging (PWI) was used to collect perfusionparameters of bilateral cerebral watershed area from the included patients:regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV),mean transit time (MTT), time to peak (TTP). See below for specific collectionmethods. It was classified into4stages according to severity of perfusion injury,which was used as PWI baseline data. See the body of this article for specificstaging methods and criteria.4. Vascular assessment was performed for the included patients throughdigital subtraction angiography (DSA), including stenosis or occlusion sites,compensatory pathways, TICI classification, etc., which was combined with PWIbaseline data for correlation study. 5. Interventional stent placement was performed on patients who hadsymptomatic severe stenosis on extracranial internal carotid artery demonstratedby DSA, and PWI was checked72hours after stent. After conventionalmedication was performed for1week on patients who had symptomatic severestenosis on extracranial internal carotid artery, if clinical remission achieved, itwould continue and PWI would be checked3months later; intracranial stentplacement was performed on patients who had not achieved remission after1-week conventional treatment, and PWI was checked72hours after stent.Conventional medication was administrated on patients who cannot be treated byinterventional therapy due to artery occlusion, or others, and PWI was checkedafter3months. All the checked PWI was compared with baseline PWI.Results1.33patients were enrolled in the study, among who23were male,10female aged34-80(56.1±13.3); and7had TIA,26had new cerebral infarction.2.Based on DSA results, bounded by the starting points of ophthalmic arteryand posterior communicating artery, the internal carotid artery vessel was dividedinto three segments: from the starting point of internal carotid artery to the startingpoint of ophthalmic artery was the first segment, on which there are9patients hadstenosis,3occlusion, and12in total; from the starting point of ophthalmic arteryto the starting point of posterior communicating artery was the second segment,on which1patients had stenosis,2occlusion, and3in total; from the startingpoint of posterior communicating artery to the starting point of middle cerebralartery main stem was the third segment, on which8patients had stenosis,10occlusion, and18in total; so totally there were18stenosis patients and15occlusion patients. No compensatory collateral circulation was developed on3patients; Grade1mainly on5; Grade2mainly on24; Grade3mainly on1. ForTICI grades,5patients were Grade I,23Grade II, and5Grade III.3.For PWI baseline injury,7patients fell into Stage I,17Stage II,5Stage III, and4Stage IV.4. Interventional stent placement was performed on8patients withextracranial internal carotid artery stenosis and1patient with middle cerebralartery stenosis; and PWI recheck72hours after stent showed normal results.5. All the24patients treated by conventional medication were rechecked forPWI3months later, which showed betterment on11patients, and no significantchanges on13patients when compared with baseline values.6.9intracranial arterial stenosis patients who did not undergo interventionwere treated by conventional medication for3months;8patients were recheckedfor CTA or MRA;1patients had vascular occlusion on lesions.7.33patients had no exacerbation of clinical symptoms within3months.Conclusion1. PWI has definite effect on evaluation of hemispheric perfusion injurycaused by unilateral carotid artery ischemia;2. The degree of unilateral internal carotid artery stenosis or perfusion injuryafter occlusion is related to age and TICI grade;3. Interventional stent placement can rapidly and significantly improvecerebral perfusion injury;4. Conventional medication can effectively control the aggravation ofperfusion injury within3months of ischemic occurrence, but cannot prevent theaggravation of some artery stenosis.