Imaging Study On The Middle Cerebral Artery Atherosclerosis

Part One: Measurement of the Middle Cerebral ArteryAtherosclerosis StenosisOBJECTIVE: Digital subtraction angiography、magnetic resonance angiography、high-resolution MRI vessel wall imaging and computed tomography angiography have allattempted to classify stenosis. Our purpose was to compare the four methods in measuringthe middle cerebral artery stenosis.METHODS: Thirty-one patients underwent DSA for known the middle cerebralartery steno-occlusive,then accomplished3D time-of-flight (TOF) MRA、high-resolutionMRI vessel wall imaging and CTA in a week.Comparison of3D TOF-MRA、high-resolution MRI vessel wall imaging and CTA for the evaluation of the middle cerebralartery atherosclerotic steno-occlusive.steno-occlusive were categorized as mild (0–50%),moderate (50–69%), severe (70–99%), or occlusive (no flow detected).RESULTS: DSA was the reference standard. Four of the thirty-one patients hadbilateral middle cerebral steno-occlusive In the thirty-seven artery,mild of43.24%(16/37),moderate of29.73%(11/37), severe of13.51%(5/37), occlusive of13.51%(5/37).3DTOF-MRA、high-resolution MRI vessel wall imaging and CTA could assess the middlecerebral atherosclerosis stenosis and grade it.CONCLUSIONS:3D TOF-MRA、high-resolution MRI vessel wall imaging andCTA were similar to DSA in evaluation the middle cerebral atherosclerosis stenosis. Part Two: The relationship between the degree of the middlecerebral stenosis and CT perfusionOBJECTIVE: To evaluate the application value of cerebral CT perfusion (CTP) of320detector row CT in cerebral ischemia caused by stenosis or occlusion of the middlecerebral artery(MCA) METHODS: Thirty nine patients with unilateral stenosis or occlusion of MCAdiagnosed by DSA.To discriminate the ischemic focus, the parameter maps of cerebralblood flow (CBF),cerebral blood volume (CBV),mean transit time (MTT),time to peak(TTP) and Delay were obtained.Analysis the relationship between the degree of MCAstenosis and five CTP parameter.RESULTS: The degree of MCA stenosis and CBV,TTP,MTT,Delay are positivecorrelative;but is not related to CBF. If the degree of MCA stenosis is different,differencesare in CBF increase,CBV increase,TTP increase and Delay increase.CONCLUSIONS: The degree of MCA stenosis is related to CBV,TTP and MTT.Themore narrow of MCA,the more CBV,TTP MTT and Delay increase. Part Three: Analysis the middle cerebral atherosclerotic plaque andevaluate the effects of drugs on itOBJECTIVE: Analysis the middle cerebral atherosclerotic plaque location and itscause.Assess the index of remodeling of the middle cerebral artery.Evaluate the effects ofdrugs on the middle cerebral atherosclerotic plaque patients who chose Aspirin(anticoagulation), Clopidogrel hydrogen sulfate (anticoagulation), Atorvastatin(lipid-lowing agent) profess to convinced three months.METHODS:64cases of the middle cerebral atherosclerotic were examined with3.0T MRI(3-dimensional time-of-flight and high-resolution MRI vessel wallimaging).Analysis the plaque location and thickness.The plaque area ratio was defined asplaque area/cross-sectional area of the vessel(VA);Remodeling ratio was defined asVA/average of the proximal and distal normal artery.Luminal area of the vessel(LA) ratiowas defined as LA/average of the proximal and distal normal artery. Fifteen patientsreceived three kinds of drugs for three months and rescaning MRI again.The plaque area atthe same time was reviewed.RESULTS：The middle cerebral atherosclerotic plaque most frequently form annularplaque and locate at the ventral and inferior wall.Plaque thickness was mainly between0.5mm and1.5mm,about72.5%.The middle cerebral atherosclerotic plaque remodeling modes were found:positive (outward) remodeling Reviewing three months drugstheropy,plaque area change were calculated in paired t test,P=0.002<0.05.CONCLUSIONS: The middle cerebral atherosclerotic plaque mostly form annularplaque and locate at the ventral and inferior wall. The plaque area ratio correlate to LAratio negatively; Remodeling ratio and LA ratio are not correlative Aspirin,Clopidogrelhydrogen sulfate,Atorvastatin could play a part in plaque reduction.